Applied Mechanics and Materials Vols. 766-767

Abstract: Hard Finish Turning has been Widely Acknowledged as an Excellent Alternative for the Traditional Grinding, Especially it Enables many Intricate Machining Profiles Possible, in a Single Machining Set-up. Cubic Boron Nitride (CBN) Inserts are Usually Used for Hard Turning of Superior Hardened Steel Parts to Very High Degree of Accuracy, Geometry and Surface Texture. the Performance of CBN is of Significant Importance for Hard Finish Turning, because of the High Single Cutting Edge Cost. an Array of Experiments are Conducted with Two Different Types of Low Content CBN Insert Grades, 1) Tin Coated Insert CB7015, 2) Non Coated Insert BN250 by Using a Tool Holder MTJNL2525M16 in a LT20 Classic ACE Turning Centre. the Surface Roughness is Inspected by SJ201P Surfinish Mitutoyo Profile Tester. the Parameters Determined during the Experiments are MRR, R_a, and Tool Life in Minutes, Number of Parts Machined. A Satisfactory Match has been Reached by Comparing Mathematical Model Tool Life Using Experimental Data from the General Taylor’s Tool Life Equation and Experimentally Measured Tool Life. the Cost Analysis is Carried out by Gilbert’s Approach Indicates that the Cost Incurred per Part Produced is Lesser in Tin Coated Insert. the Proposed Methodology can Help to Optimise the Hard Finish Turning Process for AISI M2 Die Steel, and Also in Evaluating the Performance of CBN Tin Coated Insert over Non-Coated Insert.

Abstract: The Electric Discharge Machining (EDM) is one of the most widely used new techniques to machining. In this work the literature available for improving the performance measures of EDM by using suspended powders in a dielectric medium. The Powder Mixed EDM (PMEDM) is improving the material removal rate, reducing the tool wear rate and improving the surface quality of the work piece. In this work the Monel 400 has been chosen as the work material and copper coated tool as an electrode, kerosene-servotherm as dielectric fluid and silicon, graphite as suspended powders in dielectric. EDS analysis and surface topography studies are carried out to identify the performance of the tool.

Abstract: Polyurea coatings are very reactive and fast curing even at very low temperatures with exceptional mechanical properties, chemical resistance and durability. Polyurea spray coating technology is used to overcome the initial problems in surface coating such as substrate wetting,mixing and surface finish. The study deals with the analysis of morphology and tensile properties of polyurea coating. The polyurea sample is characterized by using SEM, FTIR and XRD in addition to EDAX to determine the microstructure and chemical composition. Finally Tensile Test was carried out to examine the ultimate tensile strength and young’s modulus of Polyurea using UTM.

Abstract: Advanced ceramic coating technologies are commonly used as metal coatings for internal combustion engine components and aerospace application. The thermal barrier coatings are being applied to the engine components to increasing life and improve the performance of the engine. This experimental study is focused on advanced ceramic material of Zirconia stabilized with the yttrium oxide (Zirconia 80% wt and Yttia 20 % by weight) applied on the piston crown for analyzing the performance and emission characteristics of the diesel engine. By using ceramics coated piston crown, the brake thermal efficiency and specific fuel consumption were improved as compared to that of the piston without coating. Exhaust emission level of CO, UHC and NOx are also considerably reduced using advanced ceramic metal coating techniques.

Abstract: Nitriding is the most common surface engineering technique that is being used in Titanium alloys for improving their surface properties, viz hardness, wear resistance, etc. Ti6Al4V (Grade 5) Titanium Alloy is a super alloy that exhibits excellent mechanical strength; it is highly resistance to creep at very high temperatures which maintains good surface stability. It is resistant to corrosion and oxidation. The main objective of this review paper is to study the recent research works carried on Nitriding of Ti6Al4V alloy by using, viz gas Nitriding and laser Nitriding. This process is used in the surface hardening of machine parts such as aircraft engine parts, crank pins, valve seats, gears, bush, aero engine cylinders, aero crank shafts. Gas Nitriding is a diffusional technique in which the nitrogen atoms are diffused into the surface of the metal to obtain hard surface. By Laser Nitriding is a diffusional technique by which the surface properties of the titanium alloy is enhanced. Laser nitriding process comprises of various stages, viz, transport of heat, melting effect, diffusion and convection effect. By Nitriding technique the surface hardness of super alloys like Titanium Alloy Ti6Al4V Grade 5 can be increased by increasing the hardness on the surface there by its scope of application is widened. In this paper a literature survey is carried out and the recent research works on surface engineering of Ti6Al4V alloy using gas and laser Nitriding technique is summarized.

Abstract: Abrasive jet machining (AJM) also known as abrasive micro-blasting or Pencil blasting is an abrasive blasting machining process that uses abrasives propelled by high velocity gas to erode material from the work piece. It has been applied to rough working such as deburring and rough finishing, machining of ceramics and electronic devices. AJM has become a useful technique for micro machining. It has various distinct advantages over the other non-traditional cutting methods, which are high machining versatility, minimum stresses on the substrate. This paper deals with several experiments that have been conducted by many researchers to assess the influence of abrasive jet machining (AJM) process parameters such as type of abrasive Particle , Abrasive Particle size, Jet pressure Nozzle tip distance. Various experiments were conducted to assess the influence of abrasive jet machine.

Abstract: The increase in demand for industrial automation in the manufacturing industry has exposed the significance of machine vision in quality inspection and process monitoring. Contrast to stylus instruments, the computer vision systems have the advantages of being non-contact. In the present study a novel technique has been reviewed to explore various applications of Image processing in inspection of cutting tool surfaces. Measurement and inspection of Surface roughness, Tool wear, Tool profile, Thickness of coating done on tool and Surface defects are all reviewed in this paper which will help in developing a specialized inspection system particularly for inspection of machining tools alone in reduced production cost and minimised time.

Abstract: Abrasive waterjet machining (AWJM) is one of the non-traditional machining processes used for machining hard and difficult materials including metal matrix composites (MMCs) and ceramic matrix composites (CMCs). MMCs and CMCs are widely used in the industries such as automobile, aerospace, defense, etc. In AWJM, the material is removed by a narrow stream of high pressure water along with abrasive particles. This work, reviews the research work carried out on the machining aspects of MMCs and CMCs using AJWM. Most of the research work in MMCs is carried out on aluminum based matrix reinforced with ceramics such as silicon carbide (SiC) and aluminum oxide (Al₂O₃) in various proportions. In the case of CMCs, the research work mostly are carried out on alumina (Al₂O₃) based work specimen. Generally, it is observed that the reinforcement particles in the MMCs and CMCs greatly influence the output process parameters like depth of the cut, material removal rate (MRR), surface roughness (R_a), kerf width, etc. From the literature review, it is observed that the increase in volume percentage of reinforced abrasive particles results in decreased MRR, decreased in the depth of cut and increase in the R_a. This work also covers the future research work in the machining aspects of MMCs and CMCs.

Abstract: The machining of hard turning is performed on hardened steel in the range of 45 to 68 Rockwell hardness using a variety of tool materials such as Polycrystalline cubic boron nitride (PCBN) , Polycrystalline diamond (PCD) and Cubic boron nitride (CBN). It is an alternative to conventional grinding process is a flexible and effective machining process for hardened metals and hence broadly used in various applications such as dies, moulds, tools, gears, cams, shafts, axles, bearings and forgings. Although the process is performed within small depth of cut and feed rates, estimates to reduce machining time as high as 60 % in hard turning. This paper discusses the importance of hard turning of AISI D2 steel. In this study, Experimental investigations are carried out on conventional lathe using prefixed the cutting conditions. The responses studied in the investigation are cutting forces (F_a, F_t and F_z). The cutting parameters considered for the investigation are cutting speed, feed and depth of cut. The influence of machining parameters on response is studied and presented in detail.

Abstract: It is known that the torsional extrusion process being used to create the object is complex in cross sectional profile. When compared to conventional extrusion, it is evident that the strength of the titanium alloy could be increased in torsional extrusion. This torsional extrusion process could also be applied the materials having the property of brittleness. Hence, the titanium alloys have huge application in aerospace industries in the area of jet engine components subjected to operating at extreme temperature. Besides, it is also used in critical airframe applications where high strength and fracture toughness are mandatory requirement. Further, it is also used as fasteners and tubing throughout the application of aircraft structures, since it involves a lot of complications with a huge investment for machining. This paper investigates the challenges and a difficulty in the torsional extrusion process ^[2].The material titanium is well known for its high temperature resistance and also possesses poor machining rate. Therefore, the study on Titanium machining is chosen to enrich the role of titanium alloys in the field of engineering science and materials.