Due to growing environmental concerns and economical and social problems in manufacturing sectors, there is a huge demand for the substitution of existing cutting fluids. Further, the cutting fluids selected are expected to reduce the cutting force, improve the surface roughness and also minimize the tool wear during machining operations. Hence, this paper discusses the tribological and morphological behaviour of AISI 316L stainless steel while turning under minimum quantity lubrication (MQL) such as oil–water emulsion, mineral oil, simarouba oil, pongam oil and neem oil based on Taguchi L₂₅ orthogonal array. From the extensive experimentation, it was observed that neem oil MQL with cutting speed of (140, 140, 60 m/min), feed of (0.30, 0.20, 0.10 mm/rev) and depth of cut of (1.0, 1.0, 1.0 mm) resulted in the lowest surface roughness (0.36 µm),cutting force (235.34 N) and tool wear (100.32 microns), respectively. Further, main effects plots and analysis of variance (ANOVA)can be successfully used to identify the optimum process input parameters and their percentage of contribution (P%) on the output parameters during turning of AISI 316L steel under MQL applications. The results clearly indicate that from both an ecological and economical standpoint, neem oil is the most effective lubricant in reducing cutting forces, tool wear and surface roughness during turning of AISI 316L stainless steel under MQL.

Present investigation focusses on combined effect of B₄C and SiC on the improvement in hardness with an average size of 35-40μm on Al6061 hybrid composite. Composites are produced by stir casting process. The effect of artificial aging treatment with different aging temperatures of 100, 150 and 200OC on the improvement in hardness is also investigated. Optical micrographs and Brinell hardness number have been discussed. An attempt is made to find out the intermetallic phase responsible for strengthening by Transmission Electron Microscopy. Due to positive response to age hardening treatment there is an improvement in the mechanical properties of Al6061 alloy & its hybrid composite. The aging kinetics is more accelerated in case of hybrid composites as compared to unreinforced Al6061 alloy because of presence of reinforcement particulate, which act as nucleation site for precipitation. Artificially aged at 100OC shows improvement in hardness by 120-220% due to the precipitation of secondary solute rich phase of alloying elements as compared Al6061 alloy.

In this study, we performed milling machining on carbon-epoxy polymer composites and jute-epoxy composites using a CNC vertical machining center. We focused on spindle speed, feed rate, depth of cut, and flute number and analyzed the cutting force and surface roughness. The optimal parameter combination to reduce cutting force in both composites was as follows: S = 600 rpm, FR = 100 mm/min, DOC = 0.25 mm, and FN = 6. The jute-epoxy composites required less cutting force (11.85 N/m²) compared to the carbon-epoxy composites (18.77 N/m²). The average surface roughness of the carbon-epoxy composites (6.685 µm) is higher than that of the jute-epoxy composites (3.08 µm). The type of reinforced material used greatly affects the cutting force and surface roughness during milling.

In the present experiment, the abrasive water jet machining parameters, such as water pressure, standoff distance, and traverse speed, are selected to study the effect of each parameter on the kerf taper angle and surface roughness during the machining of glass, jute, and carbon hybrid composite. The other machining parameters are kept constant. For each parameter, three levels are fixed on the basis of previous literature reviews. The Response Surface Methodology is used to design the required number of experiments and to optimize the machining parameters to obtain the minimum kerf taper angle and surface roughness. The levels selected for water pressure are 150, 220, and 250 MPa; traverse speeds are 20, 40, and 60 mm/min; and, similarly, stand-off distances are 2, 5, and 8 mm. Experimental results confirm that the parameter inversely affects both kerf angle and surface roughness. On the other hand, parameters traverse speed and stand-off distance, directly affecting both outputs. According to RSM optimization, to obtain the minimum kerf taper angle and surface roughness, we should fix the pressure at a higher level and other parameters at a lower level. For the considered range, the obtained minimum kerf angle and roughness values are 1.4982 radians and 2.0920 μm.

The high temperature phase austenite in steel has the property to transform into a variety of room temperature phases like coarse pearlite, bainite & martensite depending upon the cooling cycle. The machinability and toughness depend upon the shape and distribution of pro eutectoid harder phases. The spherical or oval shapes give lesser resistance for machining process. So it is required to design the heat treatment to tailor the property as required by the application. In this view, it is proposed to study the mechanical and micro structural properties of EN47 steel undergoing Spheroidization. The aim of this work is to test the hardness, toughness and wear property of the steel in spheroidised condition. Hardening treatment improves hardness of the material, a marginal decrease in hardness value with improved ductility is observed in tempering. Hardening and longer duration tempering show better wear resistance compared to other heat treatments. Both mild and severe wear regions are observed. Generally mild wear region is observed above five hours of continuous running of the specimen. Micro structural analysis shows the existence of pearlitic structure in as bought & normalized specimen, lath martensitic structure in hardened specimen.

The importance of medium carbon steels as engineering materials is reflected by the fact that out of the vast majority of engineering grade ferrous alloys available and used in the market today, a large proportion of them are from the family of medium carbon steels. Typically medium carbon steels have a carbon range of 0.25 to 0.65% by weight, and a manganese content ranging from 0.060 to 1.65% by weight. Medium carbon steels are more resistive to cutting, welding and forming as compared to low carbon steels. From the last two decades a number of research scholars reported the use of verity of heat treatments to tailor the properties of medium carbon steels. Spheroidizing is the novel industrial heat treatment employed to improve formability and machinability of medium/high carbon low alloy steels. This exclusive study covers procedure, the effects and possible outcomes of various heat treatments on medium carbon steels. In the present work, other related heat treatments like annealing and special treatments for property alterations which serve as pretreatments for spheroidizing are also reviewed. Medium carbon steels with property alterations by various heat treatment processes are finding increased responsiveness in transportation, aerospace, space, underwater along with other variegated fields. Improved tribological and mechanical properties consisting of impact resistance, stiffness, abrasion and strength are the main reasons for the increased attention of these steels in various industries. In the present scenario for the consolidation of important aspects of various heat treatments and effects on mechanical properties of medium carbons steel, a review of different research papers has been attempted. This review may be used as a guide to provide practical data for heat treatment industry, especially as a tool to enhance workability and tool life.