半固态条件下丁二腈-水合金的稳态流变行为

Steady State Rheological Behavior of Semisolid SCN-5at.%Wat. Alloy

采用Searle型同轴双筒剪切流变仪考察了由类金属丁二腈(SCN)和水配制的SCN-5at.%Wat.透明合金在半固态条件下的稳态流变行为。SCN-5at.%Wat.合金的稳态表观粘度表现出类似半固态金属浆料的剪切稀化现象。当冷却速率较高时,SCN-5at.%Wat.合金的稳态表观粘度随初始剪切速率的提高而减小;而当冷却速率较低时,其随初始剪切速率的提高略有增大。当初始剪切速率较低时,SCN-5at.%Wat.合金的稳态表观粘度随冷却速率的提高而增大;而当初始剪切速率较高时,其随冷却速率的提高,在较高的终了温度下表现为减小,在较低的终了温度下反而略有增大。另外,在较低初始剪切速率和较高冷却速率下,SCN-5at.%Wat.合金的稳态表观粘度总体较高。

A Searle type rheometer was used to investigate the steady state rheological behavior of semisolid SCN-5at.%Wat. transparent alloy. The steady state apparent viscosity of semisolid SCN-5at.%Wat. alloy exhibits a shear thinning phenomenon,which is similar to that for semisolid metallic alloy slurry. The steady state apparent viscosity of semisolid SCN-5at.%Wat. alloy decreases with increasing the initial shearing rate at the high cooling rate,but increases a little with increasing the initial shearing rate at the low cooling rate. At the low initial shearing rate,the steady state apparent viscosity of semisolid SCN-5at.%Wat. alloy increases with increasing the cooling rate. However,at the high initial shearing rate,it decreases with increasing cooling rate when the holding temperature is high,and increases with increasing the cooling rate when the holding temperature is low. At the low initial shearing rate and high cooling rate,the steady state apparent viscosity of semisolid SCN-5at.%Wat. alloy is always high.