Influence of direct aging heat treatment on the properties of cast and slm processed alsi10mg alloy

Abstract

Aluminium alloys find extensive use in the automotive and aviation newlinesectors owing to the intricate geometries, higher strengths, and lower densities. newlineAluminium alloys are generally processed to fabricate components through newlinevarious conventional techniques like liquid metallurgy, powder metallurgy, newlineetc. Additive manufacturing of aluminium alloys using selective laser melting newlinehas attracted significant attention in recent times, owing to its potential newlinebenefits in various industrial sectors. However, enhancement of the aluminium newlinealloy properties through different heat treatment process is still under research, newlineas the solution or T6 heat treatment degrades the properties of the alloys. So, newlinethis thesis aims to explore the influence of direct aging heat treatment on the newlinemetallurgical, mechanical, tribological and corrosion behaviour of the newlineAlSi10Mg alloy processed through conventional casting and selective laser newlinemelting. Two sets of samples were produced with two different approaches; newlinethe first set was kept as-cast and as-built, while the second set was treated at newline180ºC for 6h and kept as DA-cast and DA-built for further testing. newlineThe results of an optical microscopic image reveal a dendritic newlinestructure with an and#945;-Al phase surrounded by the eutectic Si phase for cast newlineAlSi10Mg alloy. While, for the SLM counterpart, the as-built microstructure newlineconsisted of a columnar pattern with a rotation angle of 67° between the layers newlineowing to the laser scanning pattern. On the other side, SEM micrographs of newlinethe cast AlSi10Mg alloy reveals a coarser Si eutectic phase and cellular newlinenetwork composed of a fibrous eutectic Al/Si along the cell boundaries was newlineobserved in the SLM counterpart. From the SEM micrographs of the DA-built newlineAlSi10Mg alloy, it was observed that the network of Si-rich eutectic phase newlinewas maintained even after the DA heat treatment. newline