A Study of Microstructure Behaviour of Aluminium Alloy after Heat Treatment and Machining

Abstract

Aluminium alloy Al6061 is one of the most widely used alloys in the 6000 Series. This standard structural alloy, one of the most versatile of the heat-treatable alloy is popular for medium to high strength range from transportation component to machinery and equipment application to recreation product and consumer durable. The objective of the research is to observe microstructure behaviour after heat treatment due to turning process for the Al6061 aluminium alloy and to identify the flank wear obtained from machining process of T6 treatment aluminium alloy. Heat treatment process should be carrying out in order to improve the level of the temper 6 (T6). Heat treatment process is defined as an operation or combination of operations, involving heating and cooling of the metal. T6 heat treatment is preferred due to higher value of mechanical properties compare to other heat treatment. However, after heat treatment will be done, the grinding and polishing process will be do for to checking microstructure on the surface of the metal by using optical microscope. Moreover, the machine process will be do for the aluminium alloy T6 for to know the strength of machinability of the machine. Turning process is employed and the parameter studies are cutting speed; 1000mm/min and depth of cut; 1 mm and 2 mm for investigating flank wear. The depth of cut as set to obtained variation result until the flank wear is arise in 0.3mm length that later will be used as comparison between new and worn tool effect the flank wear of the tool. Depth of cut variables was 1 mm and 2 mm while, machining speed was 1000 mm/min. significantly different is found from the result obtained. Based on the observation from this experiment, microstructural behaviour for Al6061 T6 heat treated depicts uniform structure, smaller in size of Si and dissolved grains boundary. Moreover, the Al6061 T6 heat treated is capable to machine for turning process. However, the amount of wear started to increase drastically as the cutting speed increases. Thus, shorten the tool life because heat is generated between contact surfaces while turning. Therefore, at high cutting speed the Flank Wear automatically increases the flank wear at the cutting tool. As a conclusion, aluminium alloy after heat treatment is suitable compared with standard aluminium alloy.