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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]

In just one step, a squeeze casting process was applied to produce aluminium foam sandwich panels. NaCl particles with mean sizes of 4.75 and 6.35 mm were used as space holders in different proportions. In-situ face sheet manufacturing was conducted through previously placed steel meshes in the mould. The effect of NaCl particle sizes and the proportion of each size on porosity, microstructure, and mechanical properties were investigated. Results showed a decline from 59.8% to 43.8% in the porosity amount of samples with increasing the proportion of larger NaCl particles. Accordingly, an increase in compression yield stress (from 3.2 to 6.1 kgf/mm2) and the absorbed energy were observed. Also, at the elevated densities of the sandwich panel core, the plateau stress was enhanced. The presence of Cu, Ni, Fe, and Si elements leads to the formation of brittle intermetallic compounds in the microstructure of cell walls. [ABSTRACT FROM AUTHOR]

The recent shoot-up in demand for lightweight materials with tailored properties has increased the interest of researchers, metallurgical and materials engineers towards aluminium matrix composites (AMCs). AMCs are light and rich in properties like corrosion, strength and wear. Moreover, AMCs are among the most economical compared to their counterparts due to the low cost and availability of aluminium. AMCs are gaining employment in many engineering sectors including power, construction, automobile and aerospace. Selection of suitable base materials and compatible reinforcement is of prime importance. Therefore, in the current study, an attempt has been made to develop an effective and economical silicon carbide-reinforced AMCs through stirring-assisted squeeze casting. Mechanical, metallurgical and wear investigations were done on the developed AMCs to determine the influence of ceramic addition on the base matrix. Microstructural investigations revealed grain refinement with even dispersion of silicon carbide in aluminium matrix. The ceramic reinforcement has also led to an increase of about 62% in ultimate tensile strength and 30% in microhardness of composites over the base matrix. Improvement in properties and microstructure can be attributed to grain refinement, reduction in porosity and strengthening of the aluminium matrix by the reinforcement particles. In addition, the tribological behaviour of the fabricated composites showed significant improvement with a reduction in wear rate and friction coefficient. [ABSTRACT FROM AUTHOR]

For reducing the forming cost of the PAN-based carbon fibre preforms, a water glass binder was used as a substitute for conventional silica binder. The preforms were infiltrated with an aluminium alloy melt by squeeze casting to fabricate the fibre-reinforced composites. The microstructure and properties of the composites were compared to the composites using the silica binder. In the composites, the water glass binder mainly remained in the vicinity of the fibre–aluminium interface and partially distributed in the matrix. The reaction near the interface between the alloy melt and binder was not recognised. The thermal expansion coefficient, thermal conductivity and the compressive strength of the composites using the water glass binder were approximately equivalent to those of the composite using the silica binder. Based on these results, the water glass can be used as an alternative binder to the silica sol. [ABSTRACT FROM AUTHOR]

Nowadays, Squeeze casting is considered as a convenient process for developing quality piston components. In this paper, casting methods such as squeeze casting and die casting techniques are used for compare the tensile behavior of Al-Si piston in the view of casted and heat-treated aspects. K-Nearest Neighbour (KNN) algorithm is used for predicting the tensile fracture of the squeeze casted Al-Si alloy. The proposed method is implemented in the MATLAB platform, and the tensile fracture in casting is compared with the experimental and predicted value. The scanning electron microscope analyzes the microstructural property and fractures analysis of the material. The maximum ultimate tensile strength of the casted and heat-treated specimen is 184 MPa and 297 MPa. The results indicate the proposed approach is an efficient method than the implemented Artificial neural network for predicting the tensile fracture in Aluminium-Silicon alloy materials. [ABSTRACT FROM AUTHOR]

In this paper, the microstructural evolution and mechanical properties of squeeze cast Al-Cu alloys with different amounts of Cu and Fe after T7 heat treatment were investigated using various methods, including optical microstructure (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron probe micro-analyzer (EPMA), and tensile testing. Results show that better comprehensive mechanical properties of squeeze cast Al-Cu alloys can be achieved by designing the Fe and Cu contents. These results can be attibuted to an increase in precipitate particles in the α(Al) matrix and the formation of nano-sized iron-rich intermetallics (IRIs). Ultimate tensile strength (UTS), yield strength (YS), and elongation (EL) of the Al-6.5Cu-0.6Mn-1.0Fe alloy were as high as 314 MPa, 293 MPa, and 6 %, respectively. These values were close to those of Al-Si alloys with high Fe content (1.0 %) under applied pressure, and this indicates the high potential for developing recycled squeeze cast Al-Cu cast alloys. [ABSTRACT FROM AUTHOR]

Pure aluminium and high-silicon aluminium alloy were reinforced with the discontinuous pitchbased carbon fibres by squeeze casting, then the thermal conductivity and the mechanical properties of the composites were investigated. Optical microscopy revealed that the fibres were in a random planar arrangement, and the transmission electron microscopy revealed that there is no interfacial reaction between the matrices and the fibres. The random planar arrangement of the fibres leads to the anisotropy of the composite. The fibre-reinforcement increased the thermal conductivity in the parallel direction for both pure aluminium and its alloy matrices, while the thermal conductivity decreased in the vertical direction. The increase in the elastic modulus by the reinforcement was not observed for both matrices. The proof stress of the pure aluminium increased by the reinforcement especially in the parallel direction, while that of the high-silicon alloy decreased by the reinforcement. [ABSTRACT FROM AUTHOR]

Aluminium composites reinforced with the PAN- and pitch-based short carbon fibres were fabricated by squeeze casting, then the thermal expansion behaviour of the composites was investigated. Optical microscopy revealed that the fibres were in a random arrangement on the plane parallel to the pressed plane during the melt infiltration process. TEM observation and hardness test revealed that the PAN-based fibre bonds strongly with the aluminium matrix while the pitch-based fibre bonds poorly. The difference in the bonding strength affected the thermal strain response; the heating and cooling curve approximately traced the same paths during the heating-cooling cycles for the PAN-based fibre composite, while the curve did not trace the same path for the pitch-based fibre composite. The fibre-reinforcement decreased the coefficient of the thermal expansion (CTE) of matrices in the direction parallel to the pressed plane. For example, the CTE of the pure aluminium and its composite at 333 K were 23.0 and 19.0 × 10−6/K, respectively. [ABSTRACT FROM AUTHOR]

The present work makes an attempt to model and analyse squeeze casting process by utilising design of experiments and response surface methodology. The input-output data for developing regression models and test cases is obtained by conducting the experiments. Surface roughness, ultimate tensile strength and yield strength have been measured for different combinations of process variables, namely, squeeze pressure, pressure duration, pouring temperature and die temperature. Two non-linear regression models based on central composite design (CCD) and Box-Behnken design (BBD) of experiments have been developed to establish the input-output relationships. The effects of process variables on the measured responses have been studied using surface plots. The performances of the two non-linear models have been tested for their prediction accuracy with the help of 15 test cases. It is observed that, both CCD and BBD, the non-linear regression models are statistically adequate and capable of making accurate predictions. [ABSTRACT FROM AUTHOR]

In situ composites have been studied mainly to eliminate wettability, porosity and non-uniform distribution of particulate problems in composite materials. Al-Mg2Si alloy are preferred choice of such group of alloys owing to the combination of light weight and improved mechanical properties. The morphology of Mg2Si is one of the key parameters for the wear properties. In this work, squeezed casting method was used to produce samples where porosity was aimed to be reduced and morphology of Mg2Si was altered. In addition, the wear properties of in situ A380-Mg2Si were investigated. It was found that as squeeze pressure was increased, porosity and size of Mg2Si was decreased and wear rate was increased. [ABSTRACT FROM AUTHOR]

Castings of Al-Cu-Mg alloy with different section thickness were prepared by gravity casting and squeeze casting, and microstructure and mechanical properties of the castings were studied. The experimental results show that squeeze casting results in considerable microstructure refinement and reduction of shrinkage porosity compared with gravity casting due to a marked increase in cooling rate. Therefore, the density and mechanical properties of the alloy are significantly improved in squeeze castings. With the section thickness increasing, microstructure of the alloy gets coarse due to a reduction in cooling rate, and the mechanical properties decrease monotonously. The composition variation of Cu between different steps in squeeze casting is smaller than that of gravity casting. Gravity casting leads to an inverse segregation of Cu in each step, while squeeze casting causes a normal solute concentration profile through the feeding of solidification shrinkage by applied pressure. [ABSTRACT FROM AUTHOR]

The effects of the applied pressure on the density, microstructure and tensile strength of the squeeze cast Al–Zn–Mg–Cu alloy were investigated. The density of the squeeze cast alloy increased steadily with the applied external pressure and it was almost constant with the pressure higher than 120 MPa. The applied pressure played an important role in solidification. It refined the grains, reduced the secondary dendrite arm spacing (SDAS) of the primary phase and thus improved the ultimate tensile strength, which could be explained by the changes of the heat transfer coefficients, the cooling rate and the nucleation rate induced by the applied pressure. [ABSTRACT FROM AUTHOR]

This investigation has studied the influence of the various casting variables on the quality of indirect squeeze castings primarily of aluminium alloys. The variables studied include gating design, filling velocity and squeezing pressure. The quality of the die casting was assessed by an analysis of both their surface condition and internal soundness. The cavity filling patterns with fanned gates and straight gate are compared. Straight gates are prone to cause jetting of the metal stream even at low velocities while fanned gates allow use of higher fill velocity without excessive jetting. A higher metal pressure provides a more complete fill of the die including improved compensation for solidification shrinkage. The gate velocity for cavity filling process is one of the most important factors for attaining a sound casting. Either too slow velocity or too rapid gate velocity can cause such defects as misrun, indications, jetting vortex, air entrapment, etc. Furthermore, the computer models using the UES ProCast software are conducted. [ABSTRACT FROM AUTHOR]

A coupled thermomechanical finite element model has been developed to simulate the temperature, stress and shape development during the solidification process of squeeze casting. In the model, the effect of latent heat and volume shrinkage due to solidification, and the mutual dependence of interfacial heat transfer and casting deformation were taken into account. A thermo-elasto-viscoplastic constitutive model was adopted for simulating the response of the solidified shell to the squeeze pressure, and an iterative approach was employed to calculate the displacement of the punch in each time step. The model can be used to investigate the evolution of temperature and stress distribution in the casting during the solidification process. [ABSTRACT FROM AUTHOR]

This research project investigated the process conditions of using squeeze casting process to produce aluminium alloy preforms or billets for subsequent cold forging process. The comparative effects of heat treatments, their microstructures and mechanical properties were evaluated. Through these studies and experiments, the main emphasis is on the study of commercial material Al 6061, Al 2014 and Al 356 alloys. The formability of the alloys was carried out using forward and backward extrusion test at 50% area reduction at room temperature (cold extrusion). It was found that when wrought aluminium 6061, 2014 and 356 alloys were squeeze cast to form the preforms, the preform microstructures revealed very fine microstructures that are feasible to be cold extruded. In addition, after thermal annealing treatment of 6061 squeeze cast preforms, the samples showed a similar value of work hardening exponent value of 020 as compared to the wrought aluminium alloy 6061, with a workhardening exponent value of 021 obtained from the static compression test. Wrought aluminium alloys generally cost twice the amount as compared with casting ingots. The microstructures of the squeeze cast 6061 alloy showed no visible cracks or inclusions after the deformation by extrusion. The results of the studies showed that Al 6061 preforms via squeeze cast technique may be cold extruded or formed, which provide an alternative means for the production of billets for the cold extrusion or forging process. [ABSTRACT FROM AUTHOR]

AS52 based hybrid composites reinforced with aluminium borate whiskers and SiC particulates were fabricated by a squeeze casting method. In a hybrid preform, the volume fraction of the aluminium borate whisker was 15% and that of the SiC particulate was 5%. Microstructures of the specimens were observed using OM and SEM. In the hybrid composites, the Alborex whiskers were uniformly distributed in the matrix and a few agglomerations or clusters of SiC particulates were observed. Hardness and three point bending tests were carried out to measure the mechanical properties of the specimens. The mechanical properties of the hybrid composites were higher than those of whisker reinforced composites and the hybrid composite with finer size particulates showed higher strength than the one with coarse particulates. [ABSTRACT FROM AUTHOR]

Alumina short fibre preforms were fabricated using an Al2O3 binder and infiltrated with aluminium piston alloy melt by squeeze casting. Al2O3 binder is thermodynamically more stable than the conventional SiO2 binder and reduces the fibre/matrix interfacial reaction. The effects of fibre volume fraction, temperature and heat treatment on the yield strength and tensile strength of the composite were investigated. The Al2O3 binder provided a satisfactory interfacial bond between the fibre and the matrix without any interfacial reaction or fibre damage. Aging behaviour was not changed by reinforcement. At every temperature, the composites showed the highest strength with a fibre volume fraction of 18%. The strength of the composite was improved by T6 heat treatment. Examination of the fracture surfaces and calculation of the tensile strength using the rule of mixtures indicated that the 18% fibre reinforced composite had a strong interfacial bond even at high temperatures. [ABSTRACT FROM AUTHOR]

In theory, a magnesium alloy should offer improved mechanical properties (such as higher strength and modulus) when reinforced with silicon carbide particulates or whiskers, as in the case of aluminium composites. However, unlike aluminium composites, the unique properties of magnesium composites are seldom achieved in practice, as reported in most published literature. Most of the magnesium composites reported were made using the squeeze casting technique, and the most notable effect is premature failure of the composites due to deformation and cracking of the preforms. This kind of perform damage has often been considered to result from use of excessive pressure in the squeeze infiltration step. Using computer modelling, an attempt was made to understand the relationship between preform cracking and the squeeze infiltration conditions of magnesium composites. The results of this work indicated that preform deformation and cracking can also result from improper processing temperatures. Therefore, relatively uniform temperatures in the liquid magnesium infiltrant are necessary in the fabrication of squeeze cast particulate reinforced magnesium composites to achieve acceptable mechanical properties. [ABSTRACT FROM AUTHOR]