Metallurgical Microstructure Evolution of Friction Drilling With AL6061-T6 at Various Regions of Bushing Formation

Abstract

Friction drilling is one of the non-conventional holes making process, it is a clean and chip-less operation which uses the frictional heat to create the hole on base materials. In any kind operations like machining of metal and mining of fuels the microstructure is composed with its various phases of size, variable form, and distribution (dendrites, grains, lamellae, precipitates, spherulites, pores, etc). Friction stir drilling technology is specifically designed for mining operations. The improved microstructure of the drilled holes ensures better load distribution and resistance to wear and tear. This translates into longer tool life, increased operational efficiency, and ultimately higher profitability for mining companies. The microstructure of metals plays a crucial role in the mining industry, primarily in two main aspects- extraction and processing of ores. In this microstructure of friction drilling hole of brittle cast materials like Al6061-T6, has been investigate with the help of optical microscope at various regions like Stirring Zone (SZ), Thermo Mechanical Affected Zone (TMAZ)and Heat Affected Zone (HAZ). Those zones are divided based on tool contact with work piece. It is observed that Al and Si particles are recrystallized structure. Due to thermal energy and forces acting on the material drilled hole contains few adhered at walls. At when compared with the HZA and TMAZ, SZ zone contains smaller mean particles are observed.