Effect of Pouring Temperature on Mechanical Properties and Microstructures of Aluminium Matrix Composite Strengthened by CNT with Stir Casting Method

Abstract

Aluminium matrix composite reinforced Carbon nanoTubes are widely developed because it can increase mechanical strength without reducing its ductility. One of the AMC / CNT manufacturing processes is through the stir casting method. The challenge of the Al / CNT manufacturing process is the occurrence of agglomeration and CNT not homogeneous so that the right casting parameters are needed to obtain optimal results. The purpose of this study was to analyse the effect of pouring temperature on the mechanical strength and microstructure of AA6061 by adding Carbon Nanotube (CNT) through the stir casting method. The CNT is added by 0.1% wt and pouring temperature at 700 °C, 730 °C and 760 °C. Mechanical tests carried out were tensile test, hardness test, and impact test. The highest value of hardness and tensile strength was obtained at the pouring temperature of 700 °C are78 HV and 80.97 MPa. Lower pouring temperature causes smaller grain size so that it has higher strength. The distribution of hardness values ​​at the top, middle and bottom of the specimen is not evenly distributed, but does not differ greatly for all pouring temperatures. The highest value of impact strength is obtained at the pouring temperature of 760 °C which is 0.128 J/mm2. Microstructure was shown the addition of CNTs caused the size of primary silicon and aluminium grains to be small which would increase the mechanical properties.