Sustainable Hard Machining of AISI 304 Stainless Steel Through TiAlN, AlTiN, and TiAlSiN Coating and Multi-Criteria Decision Making Using Grey Fuzzy Coupled Taguchi Method

Tool life is one of the essential parameters in sustainable manufacturing. Strengthening the life of cutting tool is a critical aspect in minimizing manufacturing costs. Enhancement of tool life during machining can be achieved through cutting fluids, different heat treatment techniques, coatings etc. Once cutting fluids reach the end of their useful life, they are considered hazardous and non-environmentally friendly fluids. Cryogenic treatment, a sub-zero heat treatment is an environmentally sustainable alternative to traditional methods, which is employed to strengthen tool life, wear resistance of cutting inserts, dimensional integrity and product quality. It is achieved through the conversion of residual austenite to martensite, carbide precipitation, eta-carbide formation, homogeneous crystal structure, improved thermal conductivity and decreased chemical degradation. The method of CT as well as the type of cutting tool have an impact on its performance. In recent years, several researches have experimented CT in order to optimize the parameters such as treatment temperature, soaking time, tempering temperature and tempering time for enhancing the performance of cutting tool. This review paper brings out the detailed study of different approaches followed in CT and their significant effect on microstructure of cutting tools. It specifically elaborates the influence of soaking time on micro-hardness, grain size, elemental composition, flank wear and tool life after CT. It has been identified as one of the most advantageous methods for cutting operations due to its ability to significantly increase tool life and surface quality through reduced tool wear via controlled CT of cutting tools at low temperatures. • It brings out the detailed study of different methods of CT and their significant effect on of cutting tools. • It describes the prime phenomenal reasons behind the enhancement of the performance of cutting tools. • It specifically elaborates the influence of soaking time on several properties of cryogenic treated tools. • It critically reviewed the papers published from 2015-2022. • It is provided with tabulated list of recently published articles highlighting their particular outcomes 

Effectiveness of cryogenic treatment on cutting tool inserts: A review

Enhancing the performance of rock cutting bit is an important aspect in reducing mining cost. To enhance their cutting characteristics, rock cutting bits are exposed to different heat treatment techniques. In this research work, an attempt has been made to strengthen the wear resistance of rock cutting bits through sub-zero heat treatment process called cryogenic treatment. The influence of cryogenic treatment (−196 °C) with different soaking duration (6, 12, 18, 24, 30, 36 h) on the microstructure of tungsten carbide (WC-Co) rock cutting bits is investigated through FESEM with the treatment mechanism being elucidated. Hardness of treated and untreated bits was measured using Vickers micro-hardness tester and the variation of crystal phases was examined through X-ray diffraction studies. Rate of bit wear was observed by performing wear studies through pin on disc tribo-meter with different load (5, 10, 15 N) and sliding speed (1, 1.5, 2 m/s). The results showcased the increase in bit hardness, microstructure transformation of martensitic phase (fcc α-Co to hcp ε-Co), hard η carbide formation (Co3W3C, Co6W6C) and enhanced wear rate for treated bit as compared to untreated bit. From the results, it was revealed that CT 24 treated bit possessed highest hardness (1078 HV) and nominal wear rate (87.50%) than UT and other CT bits under 15 N load at 2 m/s. 

Microstructural transformation analysis of cryogenic treated conical rock cutting bits for mining applications

Investigation of TiAlN, AlTiN, and TiAlSiN Coated Inserts on the Machining Performance of AISI 420 Steel and Multi-Objective Optimization of Process Parameters

The tools used in different manufacturing processes, such as milling, turning, drilling, etc., experience a significant amount of mechanical forces with rising temperatures during machining operations. They undergo various modes of damage and failures depending on their chemistry/metallurgy and surface structures. Therefore, various types of hard, textured and solid lubricant-based coatings are usually deposited on their surface in order to improve hardness, wear resistance, thermal stability, and lubrication and thereby enhance their life span. Here, in this paper, we will provide a critical review on different tool coatings used along with their texture geometries and solid lubricating properties. Initially, we will provide an overview on the basics of the tool coatings and their properties. Then, we will provide current status and future prospects of textured and solid-lubricated tool coatings. 

A. Ragavendran

Papers

Technical performance of nano-layered CNC cutting tool inserts – An extensive review