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This paper aims to investigate the wear behaviors of aged metal matrix composites and of the as-cast Al-Si alloy by using a pin-on-disk wear testing machine at room temperature.

Hypoeutectic (Al-7Si) alloy reinforced with low volume fractions of SiC particles (SiC_p) and graphite (Gr) particles were prepared by the stir-casting process. It was found that the addition of 9 Wt.% of SiC_p and 3 Wt.% of Gr particles conferred a beneficial effect in reducing the wear rate of the composites.

The worn-out surfaces of the specimens were examined using scanning electron microscopy (SEM); the extensive micro cracking occurs on the surface of the Al-7Si alloy tested at lower loads. The growth of these microcracks finally led to the delamination of the base alloy surface. The reinforcements (SiCp and Gr) particles tended to reduce the extent of plastic deformation in the surface layer, thereby reducing extensively the occurrence of micro cracking in the composites.

From the results, it is revealed that the quantity of wear rate was less for aged specimens compared to the as-cast specimens. The worn-out surfaces were studied using electron dispersive spectroscopy, and wear debris was analyzed using SEM.

The purpose of the paper is to study the dry sliding wear behavior of as-cast and heat-treated zinc-aluminum (ZA-27) alloy, reinforced with silicon carbide and graphite particles.

The alloy and composite samples were prepared with stir casting technique. Heat treatment was carried out for samples at a temperature of 370°C followed by quenching in water at room temperature. Subsequently, the heat-treated samples were aged at 180°C and quenched in water at room temperature. The wear tests were carried using pin-on-disc apparatus at room temperature at different applied loads, sliding speed and sliding distance.

The wear volume loss of as-cast samples was more compared with heat treated samples. Composites exhibited improved wear resistance than base alloy.

Hybrid metal matrix composites with heat treatment has exhibited superior wear behavior in dry sliding conditions.

This paper aims to investigate the microstructure, hardness and tribological properties of hypoeutectic (Al-7Si) matrix reinforced with fixed quantities of 3 Wt.% graphite (Gr) and x Wt.% SiCp (x = 3, 6 and 9) hybrid composites.

The composites were fabricated by stir cast technique. The microstructure, hardness and tribological measurements were carried out on the base alloy and composites. The tribological investigation was carried out on pin-on-disc wear testing machine under dry sliding condition.

The wear rate decreases with the increase of SiCp into A356-3Gr composites. The composite containing A356-9SiCp-3Gr had better hardness and good wear resistance compared to the base alloy. Scanning electron microscope (SEM) and electro dispersive spectrometry (EDS) images were used to study the reinforcement distribution and worn-out surface of the specimens.

The present paper brings out a clear picture of the various events that take place under the worn-out surfaces leading to the generation of mechanical mixed layer.

The aim of the this study is to develop a new class of composites which would be more commercially viable and environmentally sustainable via reduced resource depletion, as there has been global interest in utilization of natural resources. The dry sliding wear behavior of glass-epoxy (G-E)-based composites filled with tamarind kernel powder (TKP) in different volume fractions of fillers (0 per cent, 3 per cent and 6 per cent) was studied as per standards.

In the present study, the analysis and optimization of the wear process has been studied. The Taguchi approach to experimental design was used to identify the effect of wear parameters such as applied load, sliding velocity and sliding distance. Taguchi tools such as analysis of variance and multiple linear regression models have been used to analyze, obtain the significant parameters and evaluate the optimum combination levels of wear process parameters. The results of Taguchi analysis indicate that sliding distance was found to be the prominent parameter affecting wear volume loss compared to other wear parameters.

The G-E composites with 3 and 6 vol.% of TKP had the lowest wear volume loss. Multiple linear regression models for all the tested composites’ results well match with experimental results. Confirmation tests were conducted to validate the analysis. There was a close relationship between the experimental results and the statistical model.

However, to the best of author’s knowledge, these literature reports related to natural organic filler materials are limited to analysis of polymer matrix composite. Further, the addition of TKP particle as a potential filler has not been addressed. An attempt has been made to clarify the technical viability of TKP as a potential filler for G-E composite.

Ti_49.4Ni_50.6 (at. %) shape memory alloy (SMA) is a unique class of smart materials because of unbeatable property which given a wide variety of their applications across a broad range of fields including an orthopedic implant. It plays a very important role in the constructions of novel orthopedic implants application (like dynamic compression plate) because of lower Young’s modulus compared to other biomedical implant materials, high mechanical strength, excellent corrosion resistance and unique property like shape memory effect. Conventional machining of Ti-Ni yields poor surface finish and low dimensional accuracy of the machined components. Hence, wire electro-discharge machining (WDEM) of Ti-Ni has been performed. The purpose of this paper is to investigate the effect of variation of five process parameters, namely, a pulse-on time, pulse-off time, spark gap set voltage (SV), wire feed and wire tension on the material removal rate, surface roughness (SR), kerf width (KW) and dimensional deviation (DD), in the WDEM of Ti_49.5Ni_50.6 SMA.

The effect of machining parameters on Ti_49.4Ni_50.6 has been fully explored using WEDM with zinc coated brass wire as an electrode. In this work, L18 orthogonal array based on Taguchi method has been used to conduct a series of experiments and statically evaluate the experimental data by the use of the method of analysis of variance. Scanning electron microscope images of the machined surface, at the highest and lowest pulse-on time, have been taken to evaluate the quality of surface in terms of their SR values.

For the highest pulse-on time, it is observed that blow holes, cracks, melted droplets and craters have been formed on the machined surface with an SR of 2.744 µm, while for the lowest pulse-on time, these are not formed with an SR of 0.862 µm. It is seen that the pulse-on time is the most significant process parameter for MRR, SR and KW, while the DD is significantly affected by spark gap SV. The optimal values of the process parameters have been obtained by the method of analysis of mean and the confirmatory experiments have been carried out to validate results of optimization. Energy dispersive spectroscopy analysis of the machined surface of Ti_49.4Ni_50.6 has shown a certain amount of deposition of material on the machined surface.

This is an original paper.

This paper aims to investigate the influence of “BroncoCut-X” (copper core-ZnCu50 coating) electrode on the machining of Ti-3Al-2.5V in view of its extensive use in aerospace and medical applications. The machining parameters are selected as Spark-off Time (ST_off), Spark-on Time (ST_on), Wire-speed (S_w), Wire-Tension (WT) and Servo-Voltage (S_v) to explore the machining outcomes. The response characteristics are measured in terms of material removal rate (MRR), average kerf width (KW) and average-surface roughness (SA).

Taguchi’s approach is used to design the experiment. The “AC Progress V2 high precision CNC-WEDM” is used to conduct the experiments with ϕ 0.25 mm diameter wire electrode. The machining performance characteristics are examined using main effect plots and analysis of variance. The grey-relation analysis and fuzzy interference system techniques have been developed to combine (called grey-fuzzy reasoning grade) the experimental response while Rao-Algorithm is used to calculate the optimal performance.

The hybrid optimization result is obtained as ST_off = 50µs, ST_on = 105µs, S_w = 7 m/min, WT = 12N and S_v=20V. Additionally, the result is compared with the firefly algorithm and improved gray-wolf optimizer to check the efficacy of the intended approach. The confirmatory test has been further conducted to verify optimization results and recorded 8.14% overall machinability enhancement. Moreover, the scanning electron microscopy analysis further demonstrated effectiveness in the WEDMed surface with a maximum 4.32 µm recast layer.

The adopted methodology helped to attain the highest machinability level. To the best of the authors’ knowledge, this work is the first investigation within the considered parametric range and adopted optimization technique for Ti-3Al-2.5V using the wire-electro discharge machining.

The purpose of this paper is to analyze the surface integrity, including recast layer thickness, surface crack density, X-ray diffractions study and microhardness for Ni53.49Ti46.51 shape memory alloy (SMA) during wire-spark erosion machining.

Four persuasive process parameters, that is, spark on time (SON), spark off time (SOFF), wire feed (WF) and spark gap voltage (SV), have been chosen for the current investigation. Efforts have been done to explore the effects of above said parameters on the machined surface of Ni-Ti SMA by embracing box Behnken design of response surface methodology (RSM). Cutting speed and ten-point mean roughness (Rz) has been taken into account as response variables. Analysis of variance test was also performed for both response parameters with the coefficient of determination (R²) 0.9610 for cutting speed and 0.9252 for ten-point mean Rz.

The recast layer thickness from 7.83 to 12.13 µm was developed near the machined surface at different parametric settings. The least surface crack density was found at the lowest value of ten-point mean Rz, while most surface crack density was identified at the highest value of cutting speed. The microhardness near the machined surface was increased by approximately 1.8 times bulk-hardness of Ni53.49Ti46.51 SMA.

Some researchers have done a study on average surface roughness, but very few investigators concentrated on ten-point mean Rz. Surface crack density is an essential aspect of machined parts; other researchers have seldom reported it. The novelty of this research work is that the influence of SON, SV, WF and SOFF on cutting speed, Rz, recast layer thickness, micro-hardness and surface crack density proximate the machined surface while machining workpiece material.

The purpose of this paper is to explore the use of fly ash and graphite particles as low cost reinforcing materials for improved wear resistance, enhanced mechanical properties and reduction in density of hybrid composites.

The AlSi10Mg/fly ash/graphite (Al/FA/Gr) hybrid composite was synthesised by stir casting method. The dry sliding wear and friction behaviour of hybrid composites were studied using pin-on-disc machine by varying parameters like load and weight fraction of fly ash, and compared with the base metal alloy and aluminium-graphite composite. The tests were conducted with a constant sliding speed of 2 m/s and sliding distance of 2,400 m.

The hybrid composites exhibit higher hardness, higher tensile strength and lower density when compared to unreinforced alloy and aluminium-graphite composite. The incorporation of fly ash and graphite particles as reinforcements caused a reduction in the wear rate and coefficient of friction (COF) of the hybrid composites. The improvement in the tribological characteristics occured due to the load carrying capacity of hard fly ash particles and the formation of a lubricating film of graphite between the sliding interfaces. The wear rates and COF of unreinforced aluminium alloy and composites increase with an increase in the applied normal load. The wear rates and COF of hybrid composites decrease with an increase in the fly ash content. 9 wt.% fly ash and 3 wt.% graphite reinforced hybrid composite exhibited the highest wear resistance and lowest COF at all applied loads. Abrasive wear and delamination were dominant in the mild wear regime of aluminium alloy and composites. Due to subsurface deformation and crack propagation, plate-like wear debris were generated during delamination wear. In the severe wear regime, the dominant wear mechanism was adhesive wear with formation of transfer layers.

It is expected that these findings will contribute towards the development of lightweight and low cost aluminium products with improved tribological and mechanical properties.

The wear and friction data have been made available in this article for the use of Al/FA/Gr hybrid composites in tribological applications.

Electrical discharge machining (EDM) of hard materials like NiTi 60 alloys is important as it finds application in different sectors of engineering such as automobile, aircraft, biomedical, oil industries, etc.

The first target of this investigation is to determine the effect of process parameters such as current, voltage, pulse on time and pulse off time on the material removal rate (MRR), surface roughness (SR) and white layer formation (WLT) for NiTi 60 smart material alloy. The secondary aim is to identify the presence of surface integrity parameters such as cracks, WLT, microvoids, globules and debris formation by using the scanning electron microscopy technique and with the use of ImageJ software for die sink EDM machining of NiTi 60 alloy.

The results reveal that current is significant for MRR, voltage and current influence SR, and for WLT, voltage is a significant factor. The experimentation study also shows the generation of oxide and carbide layers on the machined surface, which were evident with the use of the X-ray diffraction technique. The presence of these oxide and carbide layers causes to form WLT on the machined surface and thereby increases the hardness of the machined surface.

Hardness test was performed with Vickers hardness tester, which gives evidence for the increase in hardness of machined surface due to the generation of WLT.

The paper aims at the bi‐objective optimization of a two‐echelon distribution network model for facility location and capacity allocation where in a set of customer locations with demands and a set of candidate facility locations will be known in advance. The problem is to find the locations of the facilities and the shipment pattern between the facilities and the distribution centers (DCs) to minimize the combined facility location and shipment costs subject to a requirement that maximum customer demands be met.

To optimize the two objectives simultaneously, the location and distribution two‐echelon network model is mathematically represented in this paper considering the associated constraints, capacity, production and shipment costs and solved using hybrid multi‐objective particle swarm optimization (MOPSO) algorithm.

This paper shows that the heuristic based hybrid MOPSO algorithm can be used as an optimizer for characterizing the Pareto optimal front by computing well‐distributed non‐dominated solutions. These aolutions represent trade‐off solutions out of which an appropriate solution can be chosen according to industrial requirement.

Very few applications of hybrid MOPSO are mentioned in literature in the area of supply chain management. This paper addresses one of such applications.