Influence of Process Parameters by Enclosed Cooling Slope Channel on Microstructures of Semi-solid ZCuSn10P1 Alloy

Abstract

Semi-solid ZCuSn10P1 alloy slurry was fabricated by a novel enclosed cooling slope channel (ECSC for short). The influence of process parameters on the microstructure and Tin segregation phenomenon of ZCuSn10P1 alloy semi-solid slurry was studied with optical microscope (OM), scanning electron microscope (SEM) and energy dispersive x-ray spectrum (EDS). The results showed that the primary α-Cu phase gradually evolved from the dendrite into worm-like or fine spherical crystal under chilling of ECSC and shearing of the gravitation. The finest microstructure, the equivalent diameter was 46 ± 3 μm, and its shape factor was 0.73, could be obtained under the conditions of the pouring temperature 1080 °C, 300 mm of cooling plate inclined at 45 degrees and 5 mm flow gap. The average concentration of Tin increased from 5.85% in the conventional casting to 6.46% in semi-solid slurry in primary α-Cu phase, and the average concentration of Tin decreased from 27.94% in the conventional casting to 20.59% in semi-solid slurry in liquid. The distribution of Tin element in microstructure was refined obviously and the dendrite segregation reduced.