Enormous applications of aluminium alloys in various key industries necessitated the development and improvement of material processing techniques. Due to simplicity in making complex shapes and low... Show More

Enormous applications of aluminium alloys in various key industries necessitated the development and improvement of material processing techniques. Due to simplicity in making complex shapes and low cost of production, the extrusion process for aluminium has gained great popularity in recent years. As the processing variables/parameters during any manufacturing process significantly effects the yield and mechanical properties of extruded products, the development of optimal process parameters combination is found to be vital for the modern manufacturing industries. Hence, the present article addresses the conducting of hot extrusion experiments with AA6061 and evaluation of optimal process parameters using a Taguchi-based GRA. To check the significance of the processing variables on the output quality and quantity, ANOVA is used. A confirmation test was done at the selected optimal processing parameters combination to validate the experimental results.

The aims of this article are to present the accuracy of springback prediction in U-bending sheet metal forming processes using finite element (FE) simulation incorporated with kinematics or mixed... Show More

The aims of this article are to present the accuracy of springback prediction in U-bending sheet metal forming processes using finite element (FE) simulation incorporated with kinematics or mixed hardening parameters that are derived from cyclic data provided by the developed cyclic loading tool. The FE simulation results in the form of springback angles are compared with the experimental results for validation. It was found that the mixed hardening model provides better simulation results in predicting springback. This is due to the capability of the isotropic hardening part of this model to describe cyclic transient and the kinematic hardening part to improve description of the Bauschinger effect. Kinematic hardening however, on its own is capable of providing relatively good springback simulation illustrated by errors of less than 8 percent. Overall, the data provided by cyclic loading from the newly developed bending-unbending tool is considered valuable for simulating springback prediction.

Medium carbon micro-alloyed forging steels are employed in various automotive components. The impetus for the use of micro alloyed (MA) steels is cost reduction due to elimination of post-forging... Show More

Medium carbon micro-alloyed forging steels are employed in various automotive components. The impetus for the use of micro alloyed (MA) steels is cost reduction due to elimination of post-forging heat treatment. Compared to conventional quenched and tempered steels micro-alloyed steels can achieve similar or more superior properties simply by properly controlling the process parameters. Forging temperature, strain, strain rate and cooling rate are some of the important process parameters that influence the flow stress and final forging product quality. In the present study, hot compression test on a micro-alloyed steel grade 38MnSiVS5 were conducted on thermo-mechanical simulator (Gleeble-3500) to study the effect of temperature and strain rate on flow stress. The results indicate that the flow stress of 38MnSiVS5 steel is greatly affected by both deformation temperature and strain rate. Obtained true stress-true strain curves showed that the flow stress of the alloy increased by increasing the strain rate and decreasing the temperature, which can be represented in terms of an exponent type Zener-Hollomon equation. Finally, the constitutive equations for the flow behavior of 38MnSiVS5 microalloyed steel were determined.

Machinability of the composites and achieving the dimensional accuracy in addition to surface finish at an economic machining rate is still the topic for numerous researchers. The current article... Show More

Machinability of the composites and achieving the dimensional accuracy in addition to surface finish at an economic machining rate is still the topic for numerous researchers. The current article describes the variation in machinability characteristics of AA6061-AlN composites under various sizes of reinforcements. Cutting speed, cutting depth and feed rate are preferred to perform the turning test. Cutting force, surface roughness and flank wear are identified to appraise the machinability characteristics. For an identical machining condition, the nano particle reinforced composite has less surface roughness and minimal flank wear and a greater cutting force than the other composites. An increment in cutting speed raises the flank wear and declines the surface roughness and cutting force for all composites. The findings from the experimental investigation help to utilize the turning process for machining the composites with various sizes of reinforcement at the economic rate of machining without compromising the surface quality.

The extrusion of copper-based aluminium alloys is difficult in the cold state. Extruding these alloys between the solidus and liquidus temperatures offer preferred properties on these alloys. In the... Show More

The extrusion of copper-based aluminium alloys is difficult in the cold state. Extruding these alloys between the solidus and liquidus temperatures offer preferred properties on these alloys. In the present work, AA2017, a copper-based aluminium alloy has been extruded in the semi-solid state. The mechanical and metallurgical properties of the alloy vary at different temperatures between the solidus and liquidus temperatures. The aim of the present work is to optimize the process parameters, namely, temperature of billet, strain rate, approach angle and percentage reduction in area on the semi-solid extrusion of AA2017 alloy. Experiments were designed according to Taguchi experimental design and L9 orthogonal array was used to conduct the experiments. Analysis of variance (ANOVA) method was used to find the significance of every process parameter on the thixo-extrusion process responses. The results indicate that percentage reduction area is the most important factor influencing the mechanical properties of thixo-extrusion specimen followed by temperature and strain rate.

In the present era, μ-EDM is a promising non-conventional micro-machining process for drilling as well as cutting of electrically conductive materials in the micron range. The objectives of the... Show More

In the present era, μ-EDM is a promising non-conventional micro-machining process for drilling as well as cutting of electrically conductive materials in the micron range. The objectives of the present research work is to investigate the influence of various parameters such as peak current, pulse ON-time, working time, and aluminium powder concentration on circularity and to find out the significant process parameters based on Taguchi method during micro hole drilling on Monel K-500 with the help of an EDM set-up. Further, a mathematical model has been developed to correlate the relationship between process parameters and circularity based on Response Surface Methodology (RSM). Circularity is increased from 1 to 1.5 A of peak current, from 0.5 to 1.5 sec of working time and from 1 to 4 gm/lit of aluminium concentration. The maximum value of circularity is obtained as 0.976 at the parametric combination of 1.2 A of peak current, 1.8 sec of working time and 3.33 (gm/lit) of Al powder concentration.

The aim of this study is the multi- objective optimization of process parameters of Al- Si alloy in powder mixed electrical discharge machining for obtaining minimum surface roughness, minimum tool... Show More

The aim of this study is the multi- objective optimization of process parameters of Al- Si alloy in powder mixed electrical discharge machining for obtaining minimum surface roughness, minimum tool wear rate, and maximum material removal rate. The important machining parameters were selected as discharge current, voltage and pulse-on time. Experiments were conducted by selecting different operating levels for the three parameters according to Taguchi's Design of Experiments. The multi-objective optimization was performed using Grey Relation Analysis to determine the optimal solution. The Grey Relation Grade values were then analysed using analysis of variance to determine the most contributing input parameter. On analysis it was found that peak current, pulse-on time, and voltage had an influence of 94.73%, 3.32% and 0.36%, respectively, on the multi-performance characteristics.