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To improve the adaptability to complex shaped products, TiC particulates (TiCp) reinforced high-manganese steel matrix (TiCp/HMS) composites were prepared by the squeeze casting infiltration method, and the microstructure and the mechanical properties of the composites were investigated, with different TiCp volume fractions (35%, 50%, 65%). Water glass was applied as binder in the TiCp preforms, in which iron powder was added to adjust the TiCp fractions, and Si powder to activate the bonding of TiCp/steel interface. The results showed that with the increase of the volume fraction, the hardness of the composites increases gradually, with the highest reaching 60.7 HRC at 65 % TiCp, which is 2.7 times that of the matrix. However, the bending strength decreases gradually, with the maximum 439.0 MPa obtained at 35% TiCp. The impact toughness of the composites changes slightly. Due to the use of water glass, brittle glass phase is formed at the TiCp/steel interface, which reduces the mechanical properties of the composites. The addition of Si powder can improve the comprehensive mechanical properties of the composites. [ABSTRACT FROM AUTHOR]

In this study, Al2219 composites with varying wt.% of Si3N4 particles using a combination of stir casting and squeeze casting techniques have been explored. Al2219 alloy with 3, 6, and 9 wt.% of Si3N4 composites was examined for the microstructures through SEM analysis, which revealed an even dissemination of the reinforcement particles within the base matrix. Remarkably, did not observe any issues such as particle agglomeration, residual porosity, or other casting-related problems. The inclusion of ceramic particles in the squeezed composites led to significant increments in hardness, tensile and yield strength, and Izod impact strength when compared to the base Al2219 matrix alloy. Notably, during compression testing, observed a considerable increase in compressive strengths, albeit at the expense of reduced failure strain, as the concentration of hard ceramic reinforcement particles increased. [ABSTRACT FROM AUTHOR]

In this paper, the microstructure evolution and properties of squeeze-cast Al–8Si-1.5Cu–1Ni-0.5Mg-0.5Mn-0.2V-0.2Ti-0.2Zr alloy (hereafter, Al–Si–Cu–Ni alloy for short) were investigated under various solution processes, evaluating the mechanical properties at room and elevated temperatures for both as-cast and T6-treated states. The results showed that following the optimal two-stage solution (i.e., solution at 510 ​°C for 6 ​h ​+ ​solution at 530 ​°C for 8 ​h) and subsequent aging at 190 ​°C for 10 ​h, referred to as the S530-T6 treatment, the Al–Si–Cu–Ni alloy exhibited excellent room/high temperature performance. The ultimate tensile strength (UTS), yield strength (YS) and elongation of the alloy at room temperature were 410 ​MPa, 368 ​MPa and 1.5 ​%, and the UTS, YS and elongation of alloy at 300 ​°C were 177 ​MPa, 170 ​MPa and 6 ​%, respectively. The increase in strength at room temperature is mainly attributed to the spheroidization of eutectic silicon and the precipitate strengthening aroused from uniformly dispersed nano-sized Q-Al 4 Cu 2 Mg 8 Si 7 , σ-Al 5 Cu 6 Mg 2 and θ′-Al 2 Cu phases, while the increase in strength at high temperature is due to the formation of heat-resistant Ni-rich phases and the improvement of the micromorphology of high melting point intermetallic compounds. [ABSTRACT FROM AUTHOR]

This manuscript proposes a hybrid method to predict the optimal nano‐metal matrix composites. The proposed hybrid technique is the wrapper of the Fire‐Hawk Optimizer (FHO) and Spiking Neural Network (SNN). Commonly it is known as FHO‐SNN method. The main objective of the proposed method is to improve the method parameters for better enhancement in mechanical properties. FHO approach is used to improve the process parameters of stirring squeeze casting method. The SNN predicts optimal parameters. Moreover, the problem based on the casting is reduced. By then the proposed hybrid technique performance is performed in the MATLAB platform and associated with various existing approaches. The proposed system shows the high tensile strength, impact energy and hardness compared with other existing methods. [ABSTRACT FROM AUTHOR]

Aluminum alloy–graphene metal matrix composite is largely used for structural applications in the aerospace and space exploration sector. In this work, the preprocessed powder particles (AA 2014 and graphene) were used as a reinforcement material in a squeeze casting process. The powder mixture contained aluminum alloy powder 2014 with an average particle size of 25 μm and 0.5 wt% graphene nano powder (Grnp) with 10 nm (average) particle size. The powder mixture was mixed using the high-energy planetary ball milling (HEPBM) technique. The experimental results indicated that the novel mixture (AA 2014 and graphene powder) acted as a transporting agent of graphene particles, allowing them to disperse homogeneously in the stir pool in the final cast, resulting in the production of an isotropic composite material that could be considered for launch vehicle structural applications. Homogeneous dispersion of the graphene nanoparticles enhanced the interfacial bonding of 2014 matrix material, which resulted in particulate strengthening and the formation of a fine-grained microstructure in the casted composite plate. The mechanical properties of 0.5 wt% graphene-reinforced, hot-rolled composite plate was strengthened by the T6 condition. When compared to the values of unreinforced parent alloy, the ultimate tensile strength and the hardness value of the composite plate were found to be 420 MPa and 123 HRB, respectively. [ABSTRACT FROM AUTHOR]

In today's manufacturing industries, Metal Matrix Composites (MMCs) are in high demand owing to their valuable properties like high strength-to-weight ratio and resistance against wear. This research evaluates the wear properties of AA2219 matrix composites reinforced using varying amounts (2%, 4% and 6% by weight) of Si3N4 particles, fabricated by squeeze casting. Wear performance testing of the developed Aluminium Matrix Composite (AMC) is executed by utilising pin-on-disc equipment subjected to varying conditions of load and speed. The wear rate is reported to rise with increasing normal load and sliding velocity. The study also reveals that the wear rate reduces with increasing reinforcement content. [ABSTRACT FROM AUTHOR]

In this study, metal matrix composite (MMC) materials were made with an aluminum matrix (AA7075 alloy) and reinforcement silicon carbide (SiC) elements using molten metal stir and indirect squeeze casting. SiC was used as a reinforcing element in the making of MMC material in different amounts (10%, 14%, and 18%) by mass. Electro Discharge Machining (EDM), cut depth (0.5 mm), three different pulse-on times, three different discharge current values, and a fixed pulse-off time (20 s) were used to machine MMC materials. The effects of machining parameters on machining time, average surface roughness, hole diameter, and material wear difference after machining were studied. As a result of the study, the composite material with 75 μ s pulse-on time, 6A current value, and 10% reinforcement element had the lowest machining time, the largest hole diameter, and the smoothest average surface. These machining parameters and materials also had the shortest machining time (5 min). Based on the signal-to-noise ratios, the best parameters for average surface roughness, hole diameter, Processing time, and material wear amount (MMC, discharge current value, and impact time) were found to be L 2 L 1 L 1 , L 3 L 1 L 1 , L 1 L 3 L 3 , and L 1 L 1 L 2 , respectively. Based on the ANOVA results, the R 2 values for the average surface roughness, hole diameter, machining time, and material wear loss value were 99.3%, 98.7%, 77.8%, and 97.3%, respectively. [ABSTRACT FROM AUTHOR]

Effects of indirect squeeze casting process parameters on the microstructure and mechanical properties of an A356.2 alloy engine hanger were studied. A 4-factor, 4-level orthogonal test was used to study the effects of applied pressure, punch velocity, pouring temperature and mold preheating temperature. The pressure, punch speed, pouring temperature and mold preheating temperature of the optimum process parameters were determined by range analysis (RA) as 100 MPa, 60 mm/s, 700 °C and 200 °C, respectively. The analysis of variance (ANOVA) showed that the only significant factor affecting the microstructure and mechanical properties was pouring temperature, while the other three factors were not significant. The specimens demonstrated mechanical characteristics akin to forged hangers, boasting a tensile strength of 297 MPa, 10.2% post-fracture elongation, and 105 HBW hardness. After T6 heat treatment, except the eutectic silicon morphology changed significantly, the microstructure basically maintained its as-cast characteristics. The samples' microstructure were categorized into three regions: coarse grain α-Al (A), eutectic structure (B), and fine grain structure (C). It was found that elevated pouring temperature could keep the pressure transmission channel open, which was helpful to improve the feeding ability and form a refined grain structure in zone C. However, with the excessive increase in casting temperature, α-Al grains in region A would be coarse, which would lead to the decline of mechanical properties. Therefore, 700 °C was determined as the best pouring temperature. [ABSTRACT FROM AUTHOR]

In order to explore the solid solution strengthening mechanism of Al-Si series alloy under semi-solid squeezing casting an experiment was conducted to cast, heat treat, and then characterize the material. OM, SEM, and TEM were selected as tools to characterize the microstructure and mechanical properties of semi-solid extrusion Al–Si–Cu–Mg alloy under different solution times. The results show that the eutectic Si phase fuses, the Al2Cu phase rapidly dissolves into the matrix, and the dislocation density in the matrix slightly decreases at the initial stage of solution. When the solution time reaches 8 h, the spheroidization degree of the eutectic Si phase reaches its optimum shape as measured by aspect ratio and size. The Al2Cu phase is essentially completely dissolved into the matrix, leading to a significant reduction in the dislocation density within the matrix. The alloy reached a relatively high mechanical properties after 1 hour of solid solution at 525 °C. The dissolution of the Cu element in the matrix and the enrichment of dislocation lines around the Si phase together contribute to strengthening the α-Al phase. Additionally, another strength peak emerges at 8 h of solid solution. The second strength peak is mainly attributed to the refinement of the eutectic Si phase and the solution strengthening of the Al2Cu phase. [ABSTRACT FROM AUTHOR]

Lightweight materials with better resistance to sliding wear are prominent candidates for automobile brake drums, clutch pads and cylinder block applications to facilitate fuel economy. This attempt is reserved to cater to materials with higher tribological quality needs. Less dense foamy pumice stone particles were involved in three different percentages (5, 10, and 15 wt%) to reinforce lightweight AZ31 Mg alloy. A stir-assisted squeeze casting technique was pursued to process the composite and refine the grain structure. A phase detection, elemental mapping and microstructure study were done through X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and scanning electron microscopy (SEM), respectively. An experimental dry sliding wear scrutiny was administered using a pin-on-disc apparatus by considering: (i) ambient and elevated temperature environments and (ii) three different levels of loads. The results reveal a significant drop in wear loss and a frictional coefficient for 15% pumice-loaded composite than the base alloy. Post-wear examination acknowledges the fact that the ambient temperature wear is governed by adhesive-abrasive wear and high temperature is by abrasive wear mechanisms. Worn-out scrutiny authenticates the presence of oxide layers and their role in lubrication. A comparative study with previous works upholds the novel magnesium composite is the right candidate for the mentioned automobile applications.

Armoured Personnel Carrier (APC) as a means to support the mobility of TNI must have high toughness so that they are not easily penetrated by bullets. The APCs are commonly made of steel due to their excellent toughness and ballistic properties, however, it has a high density that reduces their mobility. Therefore, an alternative material is needed, which is lighter but remains tough. One option is Metal Matric Composites (MMC). This research studied a composite with Al-8Zn-4Mg alloy as the matrix and 20 vol. % SiC as the reinforcement. The composite was melted in a muffle furnace, stirred at 500 rpm, and squeeze-cast at the pressure of 20 tons. The samples were then solution-treated at 500°C for 1 h and aged at 200°C for up to 100 h. Characterization included hardness and impact testing, optical microscopy, and Scanning Electron Microscope - Energy Dispersive X-ray (SEM-EDX). The samples were then thermal coated by the High-Velocity Oxygen Fuel (HVOF) method using WC-Co particles. The coated samples underwent ballistic testing in accordance with NIJ 0108.01 standard by using a type III 7.56 mm caliber projectile. The results show that the hardness and impact energy increased with aging due to the formation of Mg2Si and Mg3Zn3Al2 precipitates. Peak hardness conditions after aging for 2 h generated hardness of 90,25 HRB and impact energy of 3 Joules. The composite plate failed and was penetrated by a type III 7.56 mm caliber projectile.

Nacre-inspired metal matrix composites have received much attention due to their excellent deformation coordination ability, which can achieve the synergy of strength and ductility. The preparation of nacre-like Al matrix composites by freeze casting has been a promising application, but the continuous ceramic-rich layer affects the corrosion resistance of the composites, facing complex corrosion problems during service. In this work, the microstructure and corrosion behavior of the nacre-inspired (TiBw-TiB2)/Al composites fabricated by freeze casting and squeeze casting were systematically studied. The results indicated that the Al layers and ceramic-rich layers had little change, about 35 μm and 31 μm, respectively, with an increasing ratio of the Ti/TiB2. Meanwhile, a high Ti/TiB2 ratio resulted in an increase in the Fe-Ti intermetallic phases, which was detrimental to the corrosion performance of the composites and was prone to pitting. The electrochemical test results showed that the 3Ti7TiB2 composite had the lowest corrosion current density (15.9 μA) and intergranular corrosion depth (231 μm), indicating that it had the best corrosion resistance, which can be attributable to its stable and dense passivation film. Two different corrosion phenomena during the intergranular corrosion test existed in the present nacre-inspired (TiBw-TiB2)/Al composites: intergranular corrosion in the Al matrix layer and pitting corrosion in the ceramic-rich layer. Among all the composites, the corrosion depth of the 3Ti7TiB2 composite was the smallest and significantly less than that of the 2024Al alloy. In addition, the continuous ceramic-rich layer acted as a corrosion channel during corrosion, significantly degrading the corrosion resistance of the nacre-like Al composites. [ABSTRACT FROM AUTHOR]

In the present study, the researchers have utilized graphite as the reinforced phase of the aluminum metal matrix nanocomposites (AMMNCs) owing to its high strength and lubricating properties. The AMMNCs are processed through combined ultrasonic-stir-squeeze casting process to ensure homogeneity of the reinforced phase in the matrix while minimizing the porosity of the cast ingot. The phase and microstructure of the developed AMMNCs are investigated through characterization techniques such as x-ray diffraction and Field Emission Scanning Electron Microscopy. AMMNCs exhibit lower density in comparison with the as-cast aluminum alloy (AA2014). Hardness of the composites have improved due to addition of the reinforcement, but adversely the porosity also increases with the increase in concentration of graphite. The tribological properties of the AMMNCs are investigated under dry condition and compared with that of the as-cast AA2014. Addition of graphite improves the wear properties of the AMMNCs. However, parameters like concentration of graphite and applied load affect the wear rate considerably. Post-tribological characterization of the wear scars provide detailed information on the influence of hardness and elastic modulus on the tribological properties of the AMMNCs. [ABSTRACT FROM AUTHOR]

This research addresses the demand for biodegradable orthopedic implants by enhancing magnesium-based alloys. Biodegradable magnesium alloy-based hybrid composites, produced through squeeze casting, incorporate titanium (Ti) and hydroxyapatite (HA) particles to improve microstructure, hardness, and compressive strength. The Mg–3Zn/1Ti/1.5HA composite exhibits a 13% increase in hardness and a 15.8% enhancement in compression strength compared to the base MZA alloy. In corrosion assessments at 216 h, MZA/1Ti/1.5HA shows a 21% lower corrosion rate than MZA/1Ti/0.5HA and a 10% lower rate than MZA/1Ti/1HA. The refined grain structure and formation of protective oxide layers resulting from Ti and HA incorporation contribute to enhanced corrosion resistance. Cytotoxicity assessments reveal excellent biocompatibility, with the Mg–3Zn/1Ti/1.5HA composite exceeding an 80% relative growth rate due to the formation of bone-like apatite layer, surpassing MZA/1Ti/0.5HA and MZA/1Ti/1HA. These findings underscore the potential of squeeze-casted magnesium alloy-based hybrid composites, particularly Mg–3Zn/1Ti/1.5HA, as promising orthopedic implant biomaterials. [ABSTRACT FROM AUTHOR]

The sustainable growth of advanced material in metal matrix composites receiving the eco‐friendly hazard‐free composite via recycling waste agro products attains low fabrication cost. The prime goal of this investigation is to develop and strengthen the lightweight aluminum alloy (Al7075) composite through the conservations of 0 wt%, 5 wt%, 10 wt%, and 15 wt% agro‐waste coconut shell using squeeze cast technology. The developed aluminum alloy bio‐composites are promising the best option for replacing conventional metals in several engineering applications like automotive, structural, aerospace, and others. The synthesized Al7075 alloy bio‐composites are studied its physic‐mechanical behavior tag with ASTM standards. The density results revealed nominal improvement, and its mechanical properties of hardness, ultimate tensile strength, and elastic modulus increased significantly. Sample 4 composite contained 15 wt% coconut shell powder found 2.82 ± 0.17 g/cc density with 0.716% porosity level enhanced the hardness, Ultimate tensile strength and elastic modulus of 79 ± 1.1Hv, 238 ± 1.1 MPa and 77.89 ± 2.01 GPa, respectively. [ABSTRACT FROM AUTHOR]

The high mechanical properties, corrosion resistance and low production costs of aluminum alloys make their use in the aerospace and automobile industries attractive. Addition of reinforcement, and heat treatment are important factors in increasing the physical and mechanical properties of these alloys. In this study, squeeze casting method was used to produce aramid reinforced Al7075 matrix materials and their mechanical, physical and microstructural properties were investigated. The physical (hardness) and mechanical (tensile, flexural) properties of Aramid/Al7075 material were compared with base alloy. Then, the effects of the aging process on the hardness, tensile and flexural strengths of 8%Aramid/Al7075 material (the best mechanical properties) and base alloy were investigated. The polished surfaces of the materials and the fracture surfaces after the tensile test were examined using Scanning Electron Microscopy (SEM), while the phase characterization after aging was performed using X-ray diffraction (XRD). The highest hardness values of non-aged materials were obtained in 12% aramid reinforced material. The highest flexural and tensile stress were obtained from 8% aramid reinforced material among non-aged materials, and their strengths were determined as 454 and 278 MPa, respectively. With an increase in aging time, the mechanical and physical properties of the materials exhibited a significant improvement. However, it was observed that these properties started to decrease after a certain aging time. In heat-treated Aramid/Al7075 materials, the lowest and highest hardness values were obtained as 184 and 205 HB, respectively, after aging for 8 and 20 h. The highest tensile strength (523 MPa) of the Al7075 alloy was obtained at the end of 20 h. The highest tensile strength of aramid reinforced material was obtained as 512 MPa at 16 h aging time. [ABSTRACT FROM AUTHOR]

The influence of the transition alloying element nickel and the alkaline earth element strontium on the microstructure and tensile properties of squeeze cast Al−Si‐Cu alloy under as‐cast condition at elevated temperature of 100 °C, 200 °C and 300 °C is investigated in comparison with the conventional Al−Si‐Cu alloy (A380). Aluminum alloy A380 is alloyed and modified with 2 wt% additional nickel (Ni) and 0.02 wt% strontium (Sr). Squeeze casting is employed to cast the modified A380 under an applied pressure of 90 MPa. The results of tensile testing at the selected elevated temperatures indicate that the Ni and Sr containing A380 alloy exhibits a significantly improvement on tensile properties, specifically ultimate tensile strength and yield strength with 10 %‐30 % increases. The as‐cast microstructures of both the conventional and Ni and Sr‐containing alloys are observed by an optical microscope and further analyzed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The presence of Ni‐containing intermetallic phases with Ni addition, and the modified eutectic Si phase with refined morphologies due to the Sr addition should be responsible for the considerable enhancement on the as‐cast strengths of the squeeze cast Ni‐ and Sr‐containing alloy over those of the conventional A380 alloy. [ABSTRACT FROM AUTHOR]

In this paper, engine flywheel shell components of ZL104 aluminum alloy were formed by squeeze casting forming technology, and the effect of process parameters on mechanical properties and microstructure of the formed parts was investigated. Sixteen sets of orthogonal test schemes are designed according to four conditions of specific pressure, holding time, pouring temperature and mold temperature. After the mechanical properties of the castings under different sets of experimental conditions were analyzed, the optimum process parameters were derived from the comprehensive analysis according to tensile strength and elongation. The optimum process parameters involve a casting temperature of 655 °C, a scheme B mold temperature, a pressure holding time of 20 s and a specific pressure of 34 MPa. The average tensile strength and average elongation of the formed flywheel shell components under the optimum process conditions were 211.2 MPa and 7.7%, respectively. The microstructure of the formed parts is mainly composed of α-Al phase and eutectic silicon phase. When the process parameters are properly selected, high mechanical properties and microstructure with little cast defects were obtained in the parts formed by squeeze casting. Except for Al, Fe, Mn and Si elements are mainly enriched at the grain boundary. [ABSTRACT FROM AUTHOR]

In this study, concurrent enhancements in both strength and ductility of the Al-2Li-2Cu-0.5Mg-0.2Zr cast alloy (hereafter referred to as Al-Li) were achieved through an optimized forming process comprising ultrasonic treatment followed by squeeze casting, coupled with the incorporation of Sc. Initially, the variations in the microstructure and mechanical properties of the Sc-free Al-Li cast alloy (i.e., alloy A) during various forming processes were investigated. The results revealed that the grain size in the UT+SC (ultrasonic treatment + squeeze casting) alloy was reduced by 76.3% and 57.7%, respectively, compared to those of the GC (gravity casting) or SC alloys. Additionally, significant improvements were observed in its compositional segregation and porosity reduction. After UT+SC, the ultimate tensile strength (UTS), yield strength (YS), and elongation reached 235 MPa, 135 MPa, and 15%, respectively, which were 113.6%, 28.6%, and 1150% higher than those of the GC alloy. Subsequently, the Al-Li cast alloy containing 0.2 wt.% Sc (referred to as alloy B) exhibited even finer grains under the UT+SC process, resulting in simultaneous enhancements in its UTS, YS, and elongation. Interestingly, the product of ultimate tensile strength and elongation (i.e., UTS × EL) for both alloys reached 36 GPa•% and 42 GPa•%, respectively, which is much higher than that of other Al-Li cast alloys reported in the available literature. [ABSTRACT FROM AUTHOR]

This research presents a novel approach to overcome the stress shielding effect and non-degradability commonly observed in metallic implants, which often require revision surgery. The study introduces a hybrid metal/ceramic (Ti/HA) reinforcement within the Mg-3Zn binary alloy matrix fabricated using the squeeze casting technique. The alloy matrix incorporates 1 wt% Ti and varying weight percentages (0.5, 1, and 1.5 wt%) of hydroxyapatite (HA). Microstructure analysis revealed significant grain refinement in the alloy upon adding the hybrid reinforcement. Phase analysis using XRD confirmed the presence of Mg-Zn intermetallic phases and corresponding reinforcement phases. Vickers microhardness testing demonstrated a 14.4% (89 HV) increase in hardness for the hybrid composite with 1Ti/1.5HA compared to the unreinforced alloy and other composites. Compressive testing revealed enhanced mechanical properties in the hybrid composites. The 1Ti/1.5 HA hybrid composite displayed a 12% (121 MPa) increase in compressive yield strength (CYS) compared to the alloy, while the 1Ti/1HA hybrid composite exhibited an impressive 22.5% (217 MPa) increment in compressive strength. Corrosion performance evaluation in a phosphate-buffered saline (PBS) environment indicated that the 1Ti/1.5 HA hybrid composites demonstrated comparable corrosion performance to the unreinforced alloy, with a corrosion density of 4.53 × 10−5 μA/cm2 and a linear polarization resistance of 893 ohms. Based on the findings, the Mg-3Zn alloy with 1Ti/1.5 HA hybrid reinforcement emerges as a promising material for load-bearing biodegradable implants. [ABSTRACT FROM AUTHOR]

Semi-solid rheological squeeze forming has distinct advantages over traditional casting and forming techniques. In this study, a high-performance thin-walled CuSn10P1 alloy was successfully produced by combining liquid-metal instantaneous undercooling-induced nucleation, semi-solid slurry homogenization treatment, and semi-solid rheological squeeze forming. The effects of the forming specific pressure (MPa) and filling speed (mm/s) on the microstructure and mechanical properties of these parts were explored in this study, and the influence of the intergranular brittle phase (α-Cu + δ-Cu41Sn11 + Cu3P) content on the mechanical characteristics was determined. CuSn10P1 alloy with a Cu13.7Sn phase exhibiting a large number of spherical or nearly spherical morphological features coexisting with the high-tin solid-solution layer morphology was discovered and prepared at a mold temperature of 485 °C, specific pressure of 165 MPa, and filling speed of 22 mm/s. Parts with this microstructure had excellent mechanical properties, including an ultimate tensile strength of 419.95 MPa, yield strength of 228.89 MPa, and an elongation of 13.71%. This study illustrates the viability of semi-solid rheological squeeze casting for manufacturing high-performance thin-walled high-tin copper alloys. [ABSTRACT FROM AUTHOR]

The performance of industrial tribo-systems depends on advanced composites with superior tribological characteristics. In this study, the CoCrFeMnNi high entropy alloy (HEA) is prepared through mechanical alloying, while stir squeeze casting aided with an ultrasonic transducer is used to fabricate AA 6082 alloy and x% HEA/AA composites (where, x= 2, 4, 6, 8 in weight percentage). The effect of HEAp on dry sliding wear performance of HEA/AA composites is examined in as-cast conditions using a pin-on-disk wear tester at varying normal applied pressure (0.254 MPa, 0.509 MPa, 0.763 MPa, 1.018 MPa, and 1.273 MPa), varying sliding distance (1000 m, 2000 m, 3000 m, 4000 m, and 5000 m) and a constant sliding speed (3.5 m/sec), special emphasis is centered on response factors such as wear rate, seizure resistance, and bulk temperature upsurge. The composite showed an ability to withstand higher temperatures, and better seizure and wear resistance over the alloy. The phase identification and microstructural study were carried out using an X-ray diffractometer, field emission scanning electron microscope, and transmission electron microscope, whereas the topography of worn-out surface was examined through an optical profilometer. There was a substantial decrease in coefficient of friction, and wear rate noticed as the HEAs concentration increased, whereas in all the wear conditions, the wear rate of 8% HEA/AA composite shows maximum resilience against wear, the inclusion of HEA particles also influences the extent of the subsurface at the seizure condition. [ABSTRACT FROM AUTHOR]

The subframe is a crucial load-bearing part of the chassis, playing a significant role in ensuring the safety and reliability of the vehicle. In this study, we aim to investigate the squeeze casting process of an integrated aluminum alloy subframe. Using relevant design criteria and casting theory, we have determined the optimal squeeze casting process for the whole subframe. The experimental factors for the subframe squeeze casting include pouring temperature, die temperature, filling velocity, and pressure holding time, while the response indexes are porosity, secondary dendrite arm spacing, and solidification time. These criteria were chosen based on their importance in determining the quality and mechanical properties of the casting. By studying the squeeze casting process of the integrated aluminum alloy subframe, we hope to improve the safety and reliability of chassis components. In this manuscript, the Box–Behnken design methodology was used to design the experiment scheme, and virtual casting simulation method is used to simulate the casting, and the input–output relationship model was developed. On this basis, the optimal process parameter combination was obtained by using the mayfly algorithm based on orthogonal and chaotic strategy (MAOLC). Simultaneously, the trial production test was carried out on the squeeze casting machine to verify the optimal parameters. X-ray inspection, metallographic structure testing, and mechanics performance testing show that the casting has no casting defects and has good mechanical properties. [ABSTRACT FROM AUTHOR]

In the present investigation an attempt was made to synthesize nano-SiC/BN-reinforced Al–Zn–Mg alloy composites by varying its weight percentage of SiC (2wt%, 4wt%, 6wt%) and maintaining 3wt% BN using the squeeze casting method and comparing it with as-cast aluminium alloy. SEM and ASTM standards are used to examine the morphology and mechanical behaviour of the synthesized aluminium alloy hybrid nanocomposite. Morphological study reveals that synthesized nanocomposites show uniform distribution of reinforcement particles without indication of residual pores. Due to the presence of Mg2Si interfaces and reduction in shrinkage effects during solidification, the density and porosity of hybrid intermixtures are increased to a minimum of 0.08% and reduced to 0.0026%. In comparison with as-cast Al–Zn–Mg alloy the hardness (28.37%), tensile strength (32.53), and yield strength (34.13%), flexural (31.25%), and impact strength (27.27%) significantly improved due to enhanced wettability between the intermixture and improved grain refinement. By increasing the proportion of strengthening particles, it was found that reducible dislocation motion was observed, resulting in an improved wear rate (26.82%) of the synthesized intermixture. [ABSTRACT FROM AUTHOR]

The present study investigates the effect of the Cu/Li ratio on the porosity and microstructural evolution of two Al–Cu–Li alloys manufactured through gravity and squeeze-cast routes. The alloy with Cu/Li ~ 4 exhibits a unique compositional segregation pattern and a higher degree of preferred crystallographic orientation than the alloy with Cu/Li ~ 2, regardless of the manufacturing method (gravity or squeeze cast). A specific segregation pattern in alloy with Cu/Li ~ 4 occurs due to the preferential precipitation of Cu-rich Al2Cu and Al2CuLi precipitates and strong texture along the component { 113 } ⟨ 5 8 ¯ 1 ⟩ . Homogenization of gravity and squeeze-cast alloys reduces segregation, but the alloys produced through the squeeze-cast route have more capability to reduce segregation. The alloy with a Cu/Li ratio ~ 4 displays less response to the post-cast homogenization treatment than the alloy with a Cu/Li ratio ~ 2. The X-ray micro-computed tomography study reveals that the Cu/Li ratio greatly influences the internal and surface porosities, and it is higher for the gravity-cast alloy with Cu/Li ~ 2 than Cu/Li ~ 4. Squeeze casting helps to eliminate most of the porosities in alloys with a Cu/Li ~ 2 but leaves a considerable number of porosities in alloys with a Cu/Li ~ 4. [ABSTRACT FROM AUTHOR]

Advanced processing techniques are required to produce functionally graded metal matrix composites due to the metallurgical conditions required during production. In this study, we developed a novel approach for this task by using a combination of two different methods to produce functionally graded 7075 Al/SiCp (5–20 wt.%) composites. The first process was direct semisolid stirring, which was used to prevent particle agglomeration, brittle reaction products, floating or settling of the reinforcements, and poor wettability. The second process was sequential squeeze casting, which enabled liquid diffusion between the two composite layers that were used to produce a functionally graded aluminum matrix composite. Thus, a method was developed to eliminate the problems encountered in the production of particle-reinforced metal matrix composite materials using liquid stirring methods and to produce composite materials with the desired functionally graded structure. The resulting functionally graded material was subjected to spectrometer analyses, density measurements, and metallographic examinations to determine the characteristics of its layers and interfacial zones, as well as to assess the formation of the graded structure. The results indicate the potential of using this new combined manufacturing method, which is efficient and controllable, to produce functionally graded metal matrix composites. [ABSTRACT FROM AUTHOR]

The microstructure and compressive properties of the 7xxx series aluminum alloy (Al – 12.44Zn – 3.22Mg – 1.13Cu – 0.19Zr – 0.12Sr) reinforced with SiC whiskers via squeeze casting are investigated after aging treatments T6-1, T6-2, T6I4-1, and T6I4-2. For this purpose, the effect of four kinds of aging heat treatments on the properties of the aluminum metal matrix composites (AMMCs) is studied systematically through Vickers hardness and room temperature compressive testing. The microstructure is analyzed by optical microscopy, scanning electron microscopy, and x-ray diffraction. The experimental results show that the hardness of the AMMCs after four kinds of aging processes has different degrees of improvement compared to no-aging. After the T6-1, T6-2, T6I4-1, and T6I4-2 aging processes, the hardness of the composites is 325, 278, 306, and 345.8 HV, respectively. The additional T6-2 aging treatment provides the highest compressive strength and compressive strain, about 747 MPa and 7%, respectively, as well as a maximum dislocation strengthening of approximately 86.89 MPa. [ABSTRACT FROM AUTHOR]

In this research, effective utilization of agro waste breadfruit seed husk ash particle (SHA) as reinforcement purpose in LM25 alloy matrix enhanced with the inclusions of 3, 6, and 9wt% of graphite (Gr) nanoparticle (50nm) via squeeze cast liquid processing executed with 200MPa applied compressive pressure. This developed cast examined LM25 alloy and its composites for density, percentage of porosity, microstructure, ultimate tensile strength, abrasion, and corrosion behaviour. From the experimental result, the LM25/10wt% SHA/9wt% Gr hybrid nanocomposite has low density (2.554g/cc), an excellent ultimate tensile strength of (181±1.8 MPa), superior abrasion resistance (0.332mg/m) under 40N load at 0.75m/sec, and good corrosion resistance (0.00382mm/year) compared to cast LM25 alloy. The inclusions of SHA and Gr proved their presence in LM25 alloy has good mechanical strength and maximum abrasion and corrosion resistance to overcome the drawbacks of conventional stir-casted LM25 alloy, which is poor wear resistance. [ABSTRACT FROM AUTHOR]

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Process parameters are key to the production and cast quality of squeeze casting (SC). The exiting methods to obtain the process parameters are selected directly based on experimental results or based on the optimization through single models, which require more experiments, are expensive, time-consuming, and less adaptable. In this study, a process-parameter design method of SC based on ensemble learning is proposed, and a design and optimization framework for SC process parameters based on multi-model ensemble is established. Based on this framework, using the support vector machine (SVM), multivariate linear regression (MLR), and random forest (RF) model as the unit models, and an improved model assembling strategy (R2 weight assignment), the ensemble model (SMR) for optimizing the SC process parameters is established. Then, to obtain the optimal SC process parameters, the ant-colony-optimization (ACO) algorithm is adopted to solve the SMR model. The two application cases show that the proposed ensemble strategy is reasonable and effective; the ensemble model had higher prediction accuracy and stronger generalization ability, even in small data sample situations. Furthermore, it effectively improved the quality of cast by its designed process parameters, and the shrinkage porosity of Case 1 cast, using the designed process parameters, was reduced to 1.316%. Compared with the conventional methods for designing SC process parameters, the method based on the ensemble model is more efficient and accurate, and reduces the cost. [ABSTRACT FROM AUTHOR]

A step die made of H13 steel was utilized in this investigation cast aluminum alloy AA6061 at a pressure of 95 MPa in sections measuring 3 mm, 6 mm, 9 mm, 12 mm, and 15 mm in thickness. Surface temperatures during the squeeze casting process, as well as temperatures at distances of 3 mm, 6 mm, and 9 mm from the inner wall of the die, were recorded using K-type thermocouples. Utilizing the inverse method to solve 1-D heat conduction equations, we successfully determined the interfacial heat transferring coefficients (IHTC) and the interfacial heat flux (IHF) of the cast and die surface. The calculations revealed that with the commencement of squeeze casting, there was a significant rise in the IHTC for each of the five sectional steps. These IHTC reached their peak before they began to decline. The peak range of IHTC incrementally increased with the section thickness, from the 3 mm of Step 1 up to the 15 mm of Step 5. Moreover, the rate at which the IHTC reached its peak and then stabilized at a low level was slower for steps with greater thicknesses. [ABSTRACT FROM AUTHOR]

In this work, squeeze casting experiments of flywheel housing components with a large wall thickness difference and a complex shape were carried out with AlSi9Mg aluminum alloy. The defects, microstructures, and mechanical properties under different process parameters were investigated. Furthermore, the local pressurization process was applied to the thick-walled positions to force-feed the cast defects. The mechanical properties and microstructures at these positions were analyzed. The results showed that the surface quality of formed components was good and that local pressurization could effectively reduce the shrinkage cavity and shrinkage porosity in thick walls, but the scope and effect of forced feeding were limited. The optimum process parameters were a pouring temperature of 650 °C, a specific pressure of 48 MPa, a mold temperature of 220 °C, a local pressurization of 800 MPa, and pressure delay times of 15 s (side A) and 17 s (side B). The ultimate tensile strength, yield strength, and elongation of the formed component under validation experiments of the optimum process parameters were 201 MPa, 103 MPa, and 5.1%. Meanwhile, the fine grains of primary α-Al were mainly rosette and equiaxed grains, and the average grain size was about 40 μm. The microstructure of the eutectic silicon was acicular and was prone to segregation under pressure. According to profile morphology, the positions after pressurization were divided into a deformation zone, a direct action zone, and an indirect action zone. The coexistence of as-cast and plastic deformation microstructures was observed. The effect of local pressurization mainly involved a change in the solidification process, plastic deformation, and forced feeding. [ABSTRACT FROM AUTHOR]

Aluminum–copper-based alloy has a broad liquidus to solidus temperature range, making it susceptible to the formation defects such as pores and shrinkage pores during the process of solidification. Hence, ultrasonic vibration and squeeze casting can help to refine the microstructure and eliminate the formation of pores. In this paper, we used an optical microscope, scanning electron microscope, transmission electron microscope, differential scanning calorimetry, and thermal analysis to study the ultrasonic treatment (UT) and squeeze casting (SC) on the as-cast and heat-treated microstructure of Al–Cu–Mn alloys. The results show that a significant refinement can be obtained by the compound field compared with that of the individual field. The applied UT time is 30 s and 120 s, respectively. The smallest grain size and the finest Al2Cu particles are observed in the alloy with a treated time of 120 s. This is due to the ultrasonic field breaking the dendrites and promoting the flow of molten Al; squeeze casting increases the cooling rate and stimulates the nucleation temperature of α-Al. The size of the θ′ phase after compound field treatment is smaller because more Cu atoms are dissolved in the Al matrix, so the θ' strengthening phase is finely dispersed in the Al alloy matrix. It is concluded that the compound field of UT and SC is a potentially advantageous process to refine the microstructure of Al alloys. [ABSTRACT FROM AUTHOR]

In this study, a magnesium alloy injection molding device was designed based on the principle of indirect squeeze casting. The alloy system of Mg–Zn–Mn–Y was manufactured using the injection molding technology. The injection molding samples exhibit a significantly refined microstructure compared to gravity casting samples. Furthermore, the compressibility of the injection molding samples displays notable improvement over gravity casting samples. In addition, the compressive strength increases gradually with higher Y content. However, the thermal conductivity continuously declines after adding Y, and the thermal conductivity of the injection sample is lower than that of the gravity casting sample. Additionally, the T6 treatment leads to further improvements in both the compressibility and thermal conductivity of the alloy. Overall, the experiment successfully designed a magnesium alloy system with high strength and thermal conductivity. Moreover, the injection molding device has proved effective in improving compression performance and rapidly designing new alloy compositions in a laboratory setting. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate the effect of heat treatment (T6) on the microstructure, mechanical, and corrosion properties of Al 319.0 alloy. In particular, Al 319.0 alloy is developed by squeeze casting using 200 MPa pressure, and further the ingots are solutionized, quenched and artificially aged to develop a homogenous microstructure, improve distribution of secondary phase(s), and mechanical properties at ambient and elevated temperatures. The phase and microstructure of the as-cast and heat-treated Al 319.0 alloys analyzed using X-ray diffraction, optical microscope, and field emission scanning electron microscope illustrate cast ingot contain α-Al as a primary phase and Al2Cu, eutectic Si, and Al5Si7Cu-containing intermetallic as secondary phase(s). However, heat treatment leads to complete dissolution of Al5Si7Cu and partial dissolution and re-precipitation of Al2Cu phase. Moreover, heat treatment changes the morphology of eutectic Si into spheroidal Si, blocky Al2Cu into spheroids Al2Cu, and the heat-resistant α(FeMn), Al8Cu3Mn(Si) phases emerged. The tensile test at room and elevated temperatures exhibit significant improvement in the YS and UTS at ambient temperature in heat-treated alloy owing to the presence of precipitation-hardened phases. Importantly, these phases are found stable up to 150 °C and tend to coarsen at 250 °C owing to thermal softening invariably leading to a substantial reduction in mechanical properties. Potentiodynamic polarization and electrochemical impedance spectroscopy shed light on galvanic corrosion phenomena predominant in 0.1 M NaCl solution. In particular, heat-treated alloy specimens demonstrated the lowest corrosion current (Icorr—~1.72 μA/cm2), and highest polarization resistance (Rp—12260 Ω.cm2) implying superior corrosion resistance as compared to as-cast alloy owing to protective barrier provided by finer Al2Cu precipitates and spheroidal Si. [ABSTRACT FROM AUTHOR]

The present study investigates the effect of wall thickness on the mechanical properties of Al-5Mg-2.2Si-0.6Mn-0.1Ce castings, using squeeze casting to fabricate alloys with varying wall thicknesses. The results show that changes in wall thickness affect defect generation, grain size, and secondary dendrite arm space (SDAS), which in turn influence the tensile properties of the material. Specifically, the shrinkage porosity of the castings decreases gradually with increasing wall thickness, while the SDAS and grain size increase. Although this reduces defects and improves the tensile properties, the increase in SDAS and grain size leads to a decrease in yield strength and tensile strength. Notably, the material's tensile strength reaches its maximum (265.5 MPa) at a wall thickness of 10 mm. These findings demonstrate the importance of optimizing wall thickness parameters for complex castings, with potential implications for industrial production and application. [ABSTRACT FROM AUTHOR]

Rheological squeeze casting is a novel metal forming process, which can realize the integration of preparation and forming, and achieve the effect of energy saving and emission reduction. In order to investigate the application of rheological squeeze casting process on beryllium bronze alloy and to verify the improvement in beryllium bronze properties under the condition of rare-earth lanthanum addition, in this paper, a beryllium bronze workpiece with rare-earth La (0–0.30 wt%) was formed by rheological squeeze casting. The results revealed that with the increase in La content, the grain size gradually refined and became spherical, and the hardness increased from 158 to 213 HBW (by 34.8%). The rheological squeeze casting process greatly improves the nucleation rate, resulting in grain refinement. La and its compounds result in constitutional undercooling and heterogeneous nucleation, and the pressure applied in the rheological squeeze casting process affects solute diffusion and deepens the degree of undercooling. The dual effects of these aspects enhance grain refinement and result in an increase in hardness. [ABSTRACT FROM AUTHOR]

Microwave Assisted Self-propagating High-temperature Synthesis (MASHS) was used to prepare open-porous MAX phase preforms in Ti-Al-C and Ti-Si-C systems, which were further used as reinforcements for Al-Si matrix composite materials. The pretreatment of substrates was investigated to obtain open-porous cellular structures. Squeeze casting infiltration was chosen to be implemented as a method of composites manufacturing. Process parameters were adjusted in order to avoid oxidation during infiltration and to ensure the proper filling. Obtained materials were reproducible, well saturated and dense, without significant residual porosity or undesired interactions between the constituents. Based on this and the previous work of the authors, the reinforcement effect was characterized and compared for both systems. For the Al-Si+Ti-Al-C composite, an approx. 4-fold increase in hardness and instrumental Young's modulus was observed in relation to the matrix material. Compared to the matrix, Al-Si+Ti-Si-C composite improved more than 5-fold in hardness and almost 6-fold in Young's modulus. Wear resistance (established for different loads: 0.1, 0.2 and 0.5 MPa) for Al-Si+Ti-Al-C was two times higher than for the sole matrix, while for Al-Si+Ti-Si-C the improvement was up to 32%. Both composite materials exhibited approximately two times lower thermal expansion coefficients than the matrix, resulting in enhanced dimensional stability. [ABSTRACT FROM AUTHOR]

Biodegradable drug‐eluting stents (DESs) are gaining importance owing to their attractive features, such as complete drug release to the target site. Magnesium (Mg) alloys are promising materials for future biodegradable DESs. However, there are few explorations using biodegradable Mg for cardiovascular stent application. In this present study, sirolimus‐loaded poly D, L‐lactic‐co‐glycolic acid (PLGA)‐coated/ sirolimus‐fixed/AZ91 Mg alloy‐based substrate was developed via a layer‐by‐layer approach for cardiovascular stent application. The AZ91 Mg alloy was prepared through the squeeze casting technique. The casted AZ91 Mg alloy (Mg) was alkali‐treated to provide macroporous networks to hold the sirolimus and PLGA layers. The systematic characterization was investigated via electrochemical, optical, physicochemical, and in‐vitro biological characteristics. The presence of the Mg17Al12 phase in the Mg sample was found in the x‐ray diffraction system (XRD) spectrum which influences the corrosion behavior of the developed substrate. The alkali treatment increases the substrate's hydrophilicity which was confirmed through static contact angle measurement. The anti‐corrosion characteristic of casted‐AZ91 Mg alloy (Mg) was slightly less than the sirolimus‐loaded PLGA‐coated alkali‐treated AZ91 Mg alloy (Mg/Na/S/P) substrate. However, dissolution rates for both substrates were found to be controlled at cell culture conditions. Radiographic densities of AZ91 Mg alloy substrates (Mg, Mg/Na, and Mg/Na/S/P) were measured to be 0.795 ± 0.015, 0.742 ± 0.01, and 0.712 ± 0.017, respectively. The star‐shaped structure of 12% sirolimus/PLGA ensures the bioavailability of the drugs. Sirolimus release kinetic was fitted up to 80% with the "Higuchi model" for Mg samples, whereas Mg/Na/S/P showed 45% fitting with a zero‐order mechanism. The Mg/Na/S/P substrate showed a 70% antithrombotic effect compared to control. Further, alkali treatment enhances the antibacterial characteristic of AZ91 Mg alloy. Also, the alkali‐treated sirolimus‐loaded substrates (Mg/Na/S and Mg/Na/S/P) inhibit the valvular interstitial cell's growth significantly in in‐vitro. Hence, the results imply that sirolimus‐loaded PLGA‐coated AZ91 Mg alloy‐based substrate can be a potential candidate for cardiovascular stent application. [ABSTRACT FROM AUTHOR]

The study explores the development of novel composites using nano-based hybrid reinforcements to enhance mechanical and wear properties. Specifically, A356 aluminum matrix composites containing a combination of silicon carbide particles (SiCp) and multi-walled carbon nanotubes (MWCNTs) were prepared using the Rotary and Squeeze casting methods. The research aimed to investigate the mechanical properties and microstructure of A356 alloy with varying percentages (5%, 10%, and 15%) of SiC-MWCNT hybrid reinforcements added at a 2:1 ratio. The results indicated that the squeeze casting method led to refined silicon and intermetallic compounds in the microstructure, and the dispersion of SiCp in the A356 alloy was homogeneous. Grain refinement was achieved, with a notable 35.22% improvement compared to the A356 alloy without reinforcements. The addition of SiCp, intermetallics, and Si particles increased tensile and yield strength. The study also observed a reduction in Si phase and α-Al grains with increased squeeze cast parameters. Furthermore, the aspect ratio and mean diameter of Si needles decreased by 31% and 43%, respectively, compared to the base alloy. After the squeeze casting process, improvements in yield strength (17.99%), tensile strength (36.66%), and percentage of elongation (195.91%) were noted compared to the composite prepared by rotary centrifugal casting methods. Lastly, the study evaluated the machinability of the hybrid MMC through an optimization technique, Entropy-PROMETHEE (Entp-PRMT). Overall, the research demonstrates the potential of nano-based hybrid reinforcements and the squeeze casting method to enhance the mechanical properties and microstructure of A356 aluminum matrix composites, offering promising applications in various industries. [ABSTRACT FROM AUTHOR]