Effects of process parameters on microstructure and mechanical properties of ZL114A alloy under directional solidification

Directional solidification (DS) processing parameters have significant influence on microstructure of ZL114A alloy. Therefore, it is necessary to optimize DS processing parameters to control its properties. This work is aimed at studying the effect rule of DS processing parameters on microstructure of ZL114A alloy. The specimens of this alloy were prepared using high-vacuum DS equipment. In the process of DS, temperatures change from 700 °C to 800 °C, and pulling rates increase from 100 μm/s to 200 m/s. Microstructure of specimens was investigated using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). Mechanical properties of specimens were measured by means of universal tension tester and microhardness tester. Effects of melt temperatures and pulling rates on the microstructures and mechanical properties were studied and discussed. Experimental results show that the microstructure can be improved with the decrease in melting temperatures and the increase in pulling rates. However, the microstructure became coarser when the pulling rate is too higher. Therefore, a set of processing parameters were optimized as melting temperature of 700 °C and pulling rate of 150 μm/s to improve the microstructure of ZL114A alloy.