Investigation of Microstructure and Mechanical Properties of Austenite Stainless Steel 304 during Tempering and Cryogenic Heat Treatment

In the present study, the influence of heat treatment (tempering & cryogenic) on the grain orientation and few important mechanical properties of Austenite Stainless Steel 304 (ASS 304) are examined. The significant mechanical properties like ultimate strength, elongation percentage and surface hardness etc., of the experimented and untreated specimens are computed using pre standard methods and the micrographs of the specimens was conducted using metallurgical microscope. The effect of strain rate ranging from lower to higher strain rates 0.001s-1 to 0.1s-1, on true stress - true strain behaviour of tempered austenitic stainless steel 304 is investigated. Experimental results exhibited that the mechanical behaviour of ASS 304 can be reformed and improvised by several heat treatment procedures for a specific application. The results showed that the cryogenic treated specimens indicate lowest tensile strength, hardness and highest percent of elongation value compared with tempered specimen gave the maximum tensile strength, hardness and minimum percent of elongation in length value.

Performance of Cutting Tool with Cross-Chevron Surface Texture Filled with Green Synthesized Aluminium Oxide Nanoparticles

The newer methodology to improve the performance of cutting tool is by the constructive method of micro-texturing and green synthesized nanoparticles into the texture gaps for self-lubrication. Cross-chevron textures were made on the rake face of the cemented carbide tool using Neodymium Doped Yttrium Aluminium Garne (Nd-YAG) laser texturing machine. The environmentally friendly, non-hazardous and rapid method of producing nanoparticles was followed to produce Al2O3 nanoparticles. Various techniques used for characterizing the synthesized Al2O3 nanoparticles are Potential of Hydrogen (pH), Fourier Transform Infra-Red Spectroscopy Analysis (FTIR), Dynamic light scattering (DLS) and X-Ray Diffraction (XRD). The XRD shows the presence of required functional groups and the size of nanoparticles in the range of 500–550 nm. This article discusses the effect of textures, with and without nanoparticles filled on the texture gaps of the cemented carbide tool on the main cutting force, thrust force and co-efficient of friction while machining austenitic stainless steel 304. The combined effect of surface texturing and lubrication of Al2O3 nanoparticles enhanced the performance of the cutting tool compared with the conventional and textured tool.