The effect of cooling slope casting on microstructure and mechanical properties of A319 alloy after processed by equal channel angular pressing

Ishak, Nor Shwazni (2017) The effect of cooling slope casting on microstructure and mechanical properties of A319 alloy after processed by equal channel angular pressing. Project Report. Universiti Teknikal Malaysia Melaka, Melaka, Malaysia. (Submitted)

	Text (24 Pages) The Effect Of Cooling Slope Casting On Microstructure And Mechanical Properties Of A319 Alloy After Processed By Equal Channel Angular Pressing.pdf - Submitted Version Download (1MB)
	Text (Full Text) The effect of cooling slope casting on microstructure and mechanical properties of A319 alloy after processed by equal channel angular pressing.pdf - Submitted Version Restricted to Repository staff only Download (9MB)

Abstract

In this project, a feedstock of A3 l 9 alloy is produced by using cooling slope casting method. The feedstock then used for equal channel angular pressing (ECAP) using route A at room temperature. The microstructure and mechanical properties of A319 alloy before and after processed by ECAP are investigated. Some of the ECAP samples have undergone T6 heat treatment in order to evaluate the effect of heat treatment schedule on globularization of the alloy. The samples of A3 l 9 alloy was heated at 520 °C for 8 hours and then quenching in water and afterwards aging at 154 °C for 4 hours to enhance the properties of A3 l 9 alloy. All of the samples were then analyzed by optical microscope (OM) and scanning electron microscopy (SEM), hardness tests as well as tensile and fracture tests. The results revealed that the microstructure after processed by ECAP exhibits more refined structure after 1 pass. Furthermore, the structure of ECAPed A3l9 alloy had an excellent response to recovery and recrystallization mechanism refined the microstructure as compared to the cooling slope sample. The a-Al globules were less than 80 μm and the shape factor is more than 0.60. Moreover, the ECAP samples that underwent T6 heat treatment revealed the positive results in terms of homogenous distribution of phases and enhancement of mechanical properties as compared with non-heat treated sample. The Vicker's hardness value indicated that ECAPed sample promoted the higher hardness 108.0 HV to 114.5 HV after T6 heat treatment. In addition, it was observed that for ultimate tensile strength of ECAPed sample provide higher strength 191.483 MPa up to 220 MPa and high ductility of fracture behavior after T6 heat treatment. Therefore, the results revealed that the microstructural distribution and mechanical properties of the alloy were improved to a particular extent due to the highly refined grains imparted by ECAPed process.

Actions (login required)

View Item