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Nowadays, there are various industrial wastes from industries that produce lots of environmental pollution. Rice husk ash (RHA) is agricultural waste and eggshell waste is industrial waste. These wastes also produce lots of soil pollution. However, by utilizing these wastes, some environmental problems can be reduced. In the present investigation, an attempt was made to utilize RHA and eggshells as reinforcement material in the development of aluminum-based composite material. Carbonized eggshell ash (CESA) particles and RHA were ball-milled for 75 hours to obtain a single entity. The mixture of CESA and RHA particles has been varied from 2.5 % to 12.5 % in the development of the composite. Ball-milled reinforcement particles in the single entity showed uniform distribution in the aluminum-based matrix material. Results showed that after the heat treatment process, the tensile strength and hardness of the aluminum/5 % CESA/5 % RHA composite was found to be 189.95 MPa and 56 brinell hardness number (kgf/mm2) respectively. The tensile strength and hardness of the composite after heat treatment were enhanced by 31 % and 60 %, respectively. However, the toughness and ductility were reduced after adding the mixture of carbonized eggshell particles and alumina in the aluminum alloy. Corrosion loss and thermal expansion behavior were also observed to identify the carbonized eggshell and RHA addition in the aluminum alloy. Corrosion loss and thermal expansion of the AA3105/5 % eggshell powder/5 % RHA composite after heat treatment were found to be 0.011 gm and 4.35 mm3, respectively.

Lightweight and high strength materials are the primary requirements in the field of defense like in aircraft structures and aerospace applications. In this context, aluminum-based composites are one of the suitable choices because of its improved characteristics. In the present work, an attempt is made to develop aluminum (A359) based surface composites by incorporating the Si3N4 particles through friction stir processing (FSP). The numbers of FSP tool passes (single, two and three) are considered as variable parameters to evaluate its effect on various characteristics. The microstructural examination has been carried out by optical microscope and surface morphological analysis was done by scanning electron microscopy images. EDS with mapping images are used to observe the phase distribution and to identify the elements of the alloying and reinforcement materials. The elemental presences are also validated by X-ray diffraction and Raman spectroscopy. Further, mechanical properties like tensile test supported by fracture analysis and Rockwell hardness profile of the FSP zone are also discussed. In addition to it, the present work also an emphasis on the effect of the number of FSP tool passes on its wear resistance and thermal expansion. The results revealed that the value of maximum tensile strength and hardness were found to be 576 MPa and 125 HRB respectively in single pass FSPed composite. However, if the number of passes is increased then the maximum wear loss (11.7 × 10−3 g), maximum expansion due to heat (9 mm3) is observed at three-pass of FSP tool.

The mechanical behavior, physical behavior, microstructural characteristics, and corrosion behavior of AA2014/silicon carbide (SiC)/carbonized eggshell hybrid green metal matrix composites (MMCs) were investigated. Twenty-five samples of hybrid composite with different combinations of SiC and carbonized eggshell particles in AA2014 matrix alloy were prepared. Microstructure presents that the reinforcement particles (SiC and eggshells) are uniformly distributed in the matrix AA2014 alloy. Transmission electron microscope image shows proper wettability between SiC, carbonized eggshell, and AA2014 aluminum alloy. The tensile strength and the fatigue strength for the composites containing 2.5 wt.% SiC up to 7.5 wt.% carbonized eggshell were observed to be higher than that of the other selected composites. The hardness values for the composites containing 12.5 wt.% SiC and 2.5 wt.% carbonized eggshell were in all cases higher than that of the other composites. The results show that toughness decreases with the increase in the weight ratio of SiC and carbonized eggshell in the composites. The results reveal that the sample of AA2014/2.5% SiC/12.5% carbonized eggshell shows minimum corrosion rate among all the selected samples. Density, porosity, and overall cost of hybrid metal matrix composites were also calculated to see the effects of carbonized eggshell and SiC addition in AA2014 matrix alloy.

Three AA2014 alloy metal matrix composites containing reinforcing particles of eggshell, carbonized eggshell and CaCO3 (powder) were processed. The influences of different particle percentage of eggshell were compared with commercial calcium carbonate. The electromagnetic stir casting technique followed by hot extrusion was employed to fabricate metal matrix composite. The results revealed that the tensile strength, hardness and fatigue strength increased by the addition of eggshell particles up to 12.5 wt.% in AA2014 matrix alloy for both carbonized and uncarbonized reinforced composites. Toughness, ductility and corrosion rate decreased by the addition of eggshell particles up to 12.5 wt.% in AA2014 matrix alloy for both carbonized and uncarbonized reinforced composites. Mechanical properties decreased in the addition CaCO3 in AA2014 matrix alloy. After the heat treatment process, mechanical properties further improved for both carbonized and uncarbonized eggshell particles reinforced composites. However, corrosion rate increased. These results showed that using the carbonized eggshell as reinforcement in the AA2014 alloy gave better physical and mechanical properties at lower cost as compared to uncarbonized ES particles and CaCO3. Apparent interfacial reaction layer and minimum corrosion were observed at AA2014/12.5% carbonized eggshell particulate composite. No reaction product was observed at AA2014/CaCO3 particulate metal matrix composite.

The influences of weight percentage of different reinforcement particles such as SiC particles, waste uncarbonized eggshell particles, carbonized eggshell particles, and CaCO3 powder were compared in the processing of aluminium-based metal matrix composite. The results revealed that by the addition of SiC particles up to 10 wt.% and waste eggshell particles up to 12.5 wt.% in AA2014 matrix alloy, the tensile strength, hardness, and fatigue strength increased. Toughness and ductility decreased by the addition of SiC and eggshell particles in AA2014 matrix alloy. Corrosion rate decreased by the addition of SiC particle up to 7.5 wt.% and eggshell particles up to 12.5 wt.%. Results showed that hardness and heat-treatable properties are improved after the addition of SiC reinforcement particles in AA2014 aluminium alloy as compared to eggshell particles. However, porosity and overall cost increased after addition of SiC particles in AA2014 alloy. Corrosion rate increased after the heat treatment for all reinforced metal matrix composite. These results showed that using the carbonized eggshell as reinforcement in the AA2014 alloy gave better physical properties at lower cost as compared to SiC particles. Proper wettability was observed between matrix and reinforcement material for both carbonized eggshell particles and SiC particles. No wettability was observed between AA2014 alloy and CaCO3 reinforcement particles. Poor wettability reduced the mechanical properties of AA2014/CaCO3 metal matrix composite.

Chicken eggshell (ES) is an aviculture byproduct that has been listed worldwide as one of the worst environmental problems. The effective utilization of chicken eggshell (ES) biowaste is strongly encouraged in our society for environmental and economic reasons. The present work deals with development of AA2014/carbonized eggshells particulate composites by electromagnetic stir casting process at optimized parameters using RSM. The predicted tensile strength of 239 MPa of the composite was found at optimum parameters of 60 MPa (Squeezing Pressure), 12 ampere (Current), 180 s (Time) and 700°C (Pouring Temperature) respectively. There was about 2.79% error in the experimental and modeled results of tensile strength. Obtained result shows that as stirring current and stirring temperature increases, tensile strength also increases. While increase in pouring temperature of matrix decreases tensile strength of composite. Density of the metal matrix composite decreases 5%, when eggshells particulate is added 5% by wt. to matrix alloy. Hardness, toughness and fatigue strength were also carried out of the AA2014/eggshell composite. Results show an improvement in these properties with the addition of eggshell in the matrix alloy. Microstructural study show uniform distribution of eggshell in the composites.

In the present investigation, joining speed, laser power and stand-off distance were took up as joining process parameters in determining the laser transmission joining between PET films and 316 L stainless steel plates. The laser transmission joining process parameters were optimized using response methodology for obtaining maximum joint width. The Box-Behnken Design has been used to plan the experiments and response surface methodology (RSM) is selected to develop mathematical relationships between joining parameters and desired response (joint width). From the ANOVA (analysis of variance) it was concluded that stand-off distance is contributing more and it is followed by joining speed and laser power. In the range of process parameters, the result shows that joining speed increases, joint width decreases, while with the increase of laser power and stand-off distance, joint width increases. Optimum values of joining speed, laser power and stand-off distance was found to be 100 mm/min, 18 watt and 3 mm to get the maximum joint width (Predicted 2.232 mm). Corresponding average tensile strength of joint was found to be 84.38 MPa. There was approximately 6.61 % error in the experimental and modeled results of joint seam width.

Heat treatment of aluminium alloys are affected by means of precipitation hardening comprising the following steps: solutionizing, quenching and aging at room temperature (natural aging) or at elevated temperature (artificial aging). Nevertheless, during precipitation hardening of aluminium matrix-based discontinuously reinforced composites, in the solutionizing stage, the matrix alloy is modified quite significantly due to the occurrence of dislocations. The main problem faced in the heat treatment process is the selection of optimum combination of precipitation of hardening parameters for achieving the required mechanical and tribological properties of composites.

The present investigation has been focused on utilization of waste fly ash in useful manner by dispersing it in aluminum matrix to produce composite. In the present work, fly-ash which mainly consists of refractory oxides like silica, alumina, and iron oxides, was used as the reinforcing phase and to increase the wet ability magnesium and silicon were added. Composites were produced with different percentages of reinforcing phase. Al-fly ash composite is electrically conductive and can be processed by ECM, Electrical Discharge Machining (EDM).

The main problem faced in the electromagnetic stir casting is the selection of optimum combination of input variables for achieving the required mechanical properties of composites. This problem can be solved by the development of relationship between the electromagnetic parameters and the tensile strength of composite by response surface methodology. This work focuses on the review of electromagnetic stir casting parameters effect on Mechanical Properties of MMC and Hybrid MMC. From the exhaustive review, it was observed that for better mechanical properties, lower porosity and finer grain structure of composite higher stirring current, higher stirring time and lower matrix pouring temperature required.

Despite several additive manufacturing techniques are commercially available in market, Fused Deposition Modeling (FDM) is increasingly used by researchers and engineers for new product development. FDM is an established process with a plethora of advantages, but the visible surface roughness (SR), being an intrinsic limitation, is major barrier against utilization of fabricated parts for practical applications. In the present study, the chemical finishing method, using vapour of acetone mixed with heated air, is being used. The combined impact of orientation angle, finishing temperature and finishing time has been studied using Taguchi and ANOVA, whereas multi-criteria optimization is performed using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The surface finish was highly responsive to increase in temperature while orientation angle of 0&deg, yielded maximum strength, increase in finishing time led to weight gain of FDM parts. As the temperature increases, the percentage change in surface roughness increases as higher temperature assists the melt down process. On the other hand, anisotropic behaviour plays a major role during tensile testing. The Signal-to-noise (S/N) ratio plots, and ANOVA results indicated that surface finish is directly proportionate to finishing time because a longer exposure results in complete layer reflowing and settlement.

Nowadays, manufacturing industries are focusing on the green manufacturing approach. In this approach, products are manufactured without harming the environment. Utilization of industrial waste is one of the big challenges faced by worldwide. In the present study, collagen powder was extracted from the chrome containing leather waste (CCLW). This collagen powder was ball-milled with Al2O3 ceramic particles to obtain in single entity powder. Ball-milled reinforcement particles have been mixed in the aluminium alloy by different casting technique. Composite material developed by hybrid casting technique showed better mechanical and physical property as compared to conventional stir casting technique and electromagnetic stir casting technique. The microstructure of composite material developed by the hybrid casting technique showed fair distribution. Properties such as tensile strength, hardness were significantly improved by mixing the ball-milled collagen and Al2O3 particles in the single entity by hybrid casting technique. Corrosion and thermal expansion behaviours have been also identified to observe the collagen and Al2O3 particles addition in the aluminium based matrix material.

Dynamic fracture toughness (J1d) behavior of shield metal arc (SMA) welding of armor grade Armox 500 T steels prepared with low hydrogen ferritic steel (LHF) and austenitic stainless (ASS) steel consumables have been evaluated and compared. Three different techniques have been described and implemented to evaluate the dynamic fracture toughness (J1d) of investigated materials. Further, the results have been compared with Elastic plastic fracture mechanics (EPFM) approach. An investigation has also been performed regarding the influence of microstructures (for LHF and ASS weldments fusion zone) effect on dynamic fracture toughness (J1d) and fracture characteristic. Finally, a constrained optimization procedure of minimizing the mean absolute percent error (MAPE) has been used to determining the Johnson Cook (JC) hardening and Damage model for Armox 500 T to simulate the impact and damage behavior. Results revealed that, Dynamic fracture toughness (J1d) of weldment-2 (prepared by ASS consumables and consisted duplex microstructure) is 20% and 10% more than weldments-1 (prepared by LHF consumables and consisted acicular ferrite structure) and counterpart base metal (Armox 500 T). The MAPE and standard deviation between FEA and experimental results are less than 10% with a good value of regression coefficient (R) which shown the excellent prediction capability of developed model.

In this study, copper plates were welded using the microwave technique, and brass material was used as an interface. The response surface methodology was used to optimize the microwave parameters for maximum joint strength, which resulted in a value of 264 MPa in 350 s. The welding temperature was maintained at 1,100°C for maximum joint strength using a single microwave oscillator with a rated power of 890 W. A Hardness test was carried out, and the tested parameter was 79 BHN, which is a better result compared with traditional welding. The corrosion behavior of the copper welded joint was also observed to be an effect of brass when used as an interfacial material between the copper plates. Weight loss of the heat-affected zone in salt solution (5 % NaCl + 95 % water) after 96 hours was found to be zero. This result indicates that brass as a filler material also enhances the corrosion resistance of the welded joint.

A B S T R A C T A356 alloys are ever more accepted in aircraft and automobile due to their high strength-toweight ratio and its thixotropic structure (designated SSM-A356). Its specific tensile strength and rigidity are superior to other Aluminum alloys. These qualities lead to less vehicle and aircraft weight and better fuel economy. A356 based alloys have been developed with significant ductility, strength, elongation, hardness and toughness at room temperature in as-cast state. Therefore, in the present work an attempt has been made to review A356alloy based systems and it application that possesses exceptionally high ductility as well as good mechanical strength

In this study, a simple roller burnishing tool was made to operate burnishing processes on A356/5%SiC metal matrix composite fabricated by electromagnetic stir casting under different parameters. The effects of burnishing speed, burnishing force and number of burnishing passes on the surface roughness and tribological properties were measured. Scanning electron microscopy (SEM) graphs of the machined surface with PCD (insert-10) tool and roller burnished surface with tungsten carbide (WC) roller were taken into consideration to observe the surface finish of metal matrix composites. The mechanical properties (tensile strength, hardness, ductility) of A356/5%SiC metal matrix composites were studied for both unburnished samples and burnished samples. The results revealed that the roller burnished samples of A356/5%SiC led to the improvement in tensile strength, hardness and ductility. In order to find out the effects of roller burnishing process parameters on the surface roughness of A356/5%SiC metal matrix composite, response surface methodology (RSM) (Box–Behnken design) was used and a prediction model was developed relevant to average surface roughness using experimental data. In the range of process parameters, the result shows that roller burnishing speed increases, and surface roughness decreases, but on the other hand roller burnishing force and number of passes increase, and surface roughness increases. Optimum values of burnishing speed (1.5 m/s), burnishing force (50 N) and number of passes (2) during roller burnishing of A356/5%SiC metal matrix composite to minimize the surface roughness (predicted 1.232 µm) have been found out. There was only 5.03% error in the experimental and modeled results of surface roughness.

Electromagnetic stir casting is one of the simplest ways of producing defect free aluminum matrix composites. This work focuses on the fabrication of aluminum matrix composites reinforced with various weight percentages of SiC particulates and Fly-ash by modified electromagnetic stir casting route. The distribution of SiC and Fly-ash particles in the matrix was improved by providing externally argon gas into the melt during electromagnetic stirring. Five samples of hybrid composite with different combination of Fly-ash and SiC (25 μm) were prepared by electromagnetic stir casting method. Mechanical properties (tensile strength, hardness, toughness and fatigue strength) and microstructure of all five samples were analyzed. Microstructure presents that the reinforcements (SiC particulates and Fly-ash) are uniformly distributed in the matrix (A356). The results reveal that sample of A356/15 %SiC/5 % Fly-ash shows best result among all the selected samples. Density, porosity, specific strength and thermal expansion were also calculated to see the effect of Fly-ash addition.

This paper presents an experimental study on the tensile strength of 1018 mild steel plates joined by microwave welding. Three different microwave ovens with rated power of 800, 850, and 900 W and fixed frequency of 2.45 GHz were used in the present investigation. A nickel (Ni)-based metallic powder (50 μm) was used as an interfacing material between the bulk pieces. Charcoal was used as a susceptor material to facilitate microwave hybrid heating. The rated power of the microwave oven and the welding time and temperature were the principal variables that were controlled to provide the necessary combination of heat to form the weld. The response surface methodology (Box–Behnken method) was chosen to design the experiments. The results show that, with increasing rated power of the microwave oven, the tensile strength decreases, while the tensile strength increases with increasing welding time and temperature. From analysis of variance it is concluded that the welding temperature contributes most, followed by the rated power and welding time. The optimum values of rated power and welding time and temperature were found to be 800 W, 1,000 s, and 800 °C to obtain the maximum tensile strength (predicted 245.2 MPa). There was approximately 4.06 % error between the experimental and modeled results for tensile strength.

In the present investigation, A356/C355 aluminium alloys are welded by friction stir welding by controlling various welding parameters. A356 and C355 aluminium alloys materials have a set of mechanical and physical properties that are ideally suited for application in aerospace and automobile industries and not widely used because of its poor weldebility. To overcome this barrier, weldebility analysis of A356 and C355 aluminium alloys with high speed steel (Wc-Co) tool has been investgated. An attempt has been made to investigate the influence of the rotational speed of the tools, the axial force and welding speed on tensile strength of A356/C355 aluminium alloys joint. The experiments were conducted on a milling machine. The main focus of investigation is to determine good tensile strength. Response surface methodology (box Behnken design) is chosen to design the optimum welding parameters leading to maximum tensile strength. The result shows that axial force increases, tensile strength decreases. Whereas tool rotational speed and welding speed increase, tensile strength increases. Optimum values of axial force (3 /KN), tool rotational speed (900 RPM) and welding speed (75 mm/min.) during welding of A356/C355 aluminium alloys joint to maximize the tensile strength (Predicted 223.2 MPa) have been find out.

In the present investigation, A356/SiC metal matrix composite with different weight percent of reinforcements (5%, 10%, 15%) were made-up by electromagnetic stir casting. Microstructural analysis, tensile test, hardness test, impact test and fatigue tests were carried out in order to make out microstructure and mechanical properties of the composites. The outcomes of microstructural study exposed uniform distribution and low porosity. Minimum porosity was observed for the 5% of reinforcement. The mechanical results showed that the addition of SiC particles led to the improvement in tensile strength, hardness, toughness, fatigue life. It point out, type of fabrication process and percentage of reinforcement are the effectual factor influencing the mechanical properties and observed that when percentage of reinforcement increases in electromagnetic stir casting, best mechanical properties are obtained.

In numerous applications of casting, dendritic microstructure is not desirable as it results in poor mechanical properties. Enhancing the fluid flow in the mushy zone by mechanical stirring is one of the means to suppress this dendritic. Several manufacturing techniques have been invented for fabrication of metal matrix composites. One of the popular ways of generating non-dendritic microstructure is to stir the liquid metal during solidification using an electromagnetic force field. However, the main problem faced in the electro magnetic stir (EMS) casting is the selection of optimum combination of input variables for achieving the required physical, mechanical and tribological properties of composites. Therefore, in the present work an attempt has been made to review electromagnetic stir casting and its process parameters for the fabrication and refined the grain structure of metal matrix composites that possesses exceptionally good mechanical properties as well as tribological properties.

Bagasse is a waste product which was produced from the sugar industry. These wastes produce lots of environment pollution in development. Effective utilization of these wastes can reduce lots of environment pollution. In this study, a literature review is carried out to observe the bagasse as reinforcement in the development of composite. From the literature, it was notified that bagasse can be used in the development of composite.

Machining of hard material is always a big challenge for industrial application point of view. However, machining of this hard material is possible by taking appropriate machining parameters. Titanium Ti-6Al-4, Inconel 718 and Tool Steel are also very hard material. In this study, comparative machining study of these materials was discussed. From the exhaust literature of these materials, it was observed that machining of all these three types of hard material is possible with good surface finish by taking appropriate machining parameters.

Air pollution and soil pollution from organic and inorganic wastes are one of the major problems all over the world. Furthermore, disposal of these organic and inorganic wastes is very costly. In the present investigation, the organic waste considered is rice husk ash (RHA). Rice husk was collected from rice mill industries. The inorganic waste considered is fly ash. Fly ash was collected from thermal power plant industries. By utilizing these wastes in the development of composite materials, some environmental problems can be reduced. In this study, an attempt was made to develop AA6061 base composite material reinforced with different weight percentages of RHA and fly ash. Microstructure of RHA- and fly ash–reinforced composite shows proper distribution of reinforcements. Maximum tensile strength was found to be 145.5 MPa for AA6061 + 5 % RHA + 10 % fly ash composite. Minimum porosity and maximum hardness was found to be 0.80 % and 88 HRB, respectively, for AA6061 +7.5 wt% RHA + 7.5 wt% fly ash hybrid metal matrix composite. In the same way, minimum corrosion loss and minimum thermal expansion were 0.12 mg and 20 mm3 for AA6061 +7.5 wt% RHA + 7.5 wt% fly ash hybrid metal matrix composite, respectively. Minimum water absorption and minimum soil degradation was also found for AA6061 + 7.5 wt% RHA +7.5 wt% fly ash hybrid metal matrix composite. However, density of composites continuously decreases by increasing the percentage of RHA and fly ash in the development of composites.

The Editor has retracted this article (1) because concerns have been raised regarding some of the figures. Figure 3 part B appears to be a copy of Figure 3 part A, with some alterations.

Chicken eggshell waste is an industrial byproduct, and its disposal constitutes a serious environmental hazard. Chicken eggshell can be used in commercial products to produce new materials with low cost and density. Low density material which can sustain at higher temperature is a remarkable area of research. Keeping these facts in the mind, the present investigation aims to study the physical behaviour, specific strength and thermal expansion of AA2014/SiC/carbonized eggshell hybrid green metal matrix composites. Microstructure of hybrid green metal matrix shows that the reinforcement particles (SiC particulates and carbonized eggshells particles) are uniformly distributed in the matrix AA2014 alloy. Specific strength for the composites containing 2.5wt.% SiC and up to 7.5wt.% carbonized eggshell was observed to be higher than that of the other selected composites. While for the same composition (AA2014/2.5% SiC/7.5% carbonized eggshell composites), porosity was observed lower than other selected composites. The results revealed that sample of AA2014/2.5% SiC/7.5% carbonized eggshell showed minimum cross sectional area reduction after the thermal expansion at 450°C among all the selected samples. Overall costs of hybrid metal matrix composites were also calculated.

In the present investigation, A356 alloy 5 wt% SiC composite is fabricated by electromagnetic stir casting process. An attempt has been made to investigate the effect of CNC lathe process parameters like cutting speed, depth of cut, and feed rate on surface roughness during machining of A356 alloy 5 wt% SiC particulate metal-matrix composites in dry condition. Response surface methodology (Box Behnken Method) is chosen to design the experiments. The results reveal that cutting speed increases surface roughness decreases, whereas depth of cut and feed increase surface roughness increase. Optimum values of speed (190 m/min), feed (0.14 mm/rev) and depth of cut (0.20 mm) during turning of A356 alloy 5 wt% SiC composites to minimize the surface roughness (3.15μm) have been find out. The mechanical properties of A356 alloy 5 wt% SiC were also analyzed.

In this study, a simple roller burnishing tool was made to operate burnishing processes on A356/5%SiC metal matrix composite fabricated by electromagnetic stir casting under different parameters. The effects of burnishing speed, burnishing force and number of burnishing passes on the surface roughness and tribological properties were measured. Scanning electron microscopy (SEM) graphs of the machined surface with PCD (insert-10) tool and roller burnished surface with tungsten carbide (WC) roller were taken into consideration to observe the surface finish of metal matrix composites. The mechanical properties (tensile strength, hardness, ductility) of A356/5%SiC metal matrix composites were studied for both unburnished samples and burnished samples. The results revealed that the roller burnished samples of A356/5%SiC led to the improvement in tensile strength, hardness and ductility. In order to find out the effects of roller burnishing process parameters on the surface roughness of A356/5%SiC metal matrix composite, response surface methodology (RSM) (Box–Behnken design) was used and a prediction model was developed relevant to average surface roughness using experimental data. In the range of process parameters, the result shows that roller burnishing speed increases, and surface roughness decreases, but on the other hand roller burnishing force and number of passes increase, and surface roughness increases. Optimum values of burnishing speed (1.5 m/s), burnishing force (50 N) and number of passes (2) during roller burnishing of A356/5%SiC metal matrix composite to minimize the surface roughness (predicted 1.232 µm) have been found out. There was only 5.03% error in the experimental and modeled results of surface roughness.

A356/SiC metal matrix composites with different weight percent of SiC particles were fabricated by two different techniques such as mechanical stir casting and electromagnetic stir casting. The results of macrostructure, microstructure, and XRD study revealed uniform distribution, grain refinement, and low porosity in electromagnetic stir casing samples. The mechanical results showed that the addition of SiC particles led to the improvement in tensile strength, hardness, toughness, and fatigue life. It indicates that type of fabrication process and percentage of reinforcement are the effective factors influencing the mechanical properties. It is observed that when percentage of reinforcement increases in electromagnetic stir casting, best mechanical properties are obtained.

The objective of the present work is to study the effects of laser power, joining speed, and stand-off distance on the joint strength of PET and 316 L stainless steel joint. The process parameters were optimized using response methodology for achieving good joint strength. The central composite design (CCD) has been utilized to plan the experiments and response surface methodology (RSM) is employed to develop mathematical model between laser transmission joining parameters and desired response (joint strength). From the ANOVA (analysis of variance), it was concluded that laser power is contributing more and it is followed by joining speed and stand-off distance. In the range of process parameters, the result shows that laser power increases and joint strength increases. Whereas joining speed increases, joint strength increases. The joint strength increases with the increase of the stand-off distance until it reaches the center value; the joint strength then starts to decrease with the increase of stand-off distance beyond the center limit. Optimum values of laser power, joining speed, and stand-off distance were found to be 18 watt, 100 mm/min, and 2 mm to get the maximum joint strength (predicted: 88.48 MPa). There was approximately 3.37% error in the experimental and modeled results of joint strength.