钨基合金系挤压喂料粘度与流变特性研究

Research on Viscosity and Rheological Properties of Tungsten-Based Alloy PEM Feed

摘要:

为了获得有利于成形的粘结剂优化配方，对相同粉末装载量的4种粘结剂体系的93W-Ni-Fe 粉末増塑挤压成形喂料粘度和流变行为进行了研究。采用英国AR2000EX旋转流变仪对钨基合金系挤压料在不同温度、不同剪切速率下的粘度进行测算。结果表明：对于不同粘结剂组成的喂料A、B、C和D中，A的粘度较低，流动性能较好，喂料D流变性能最不稳定；根据剪切速率与粘度的关系曲线可测算出130 ℃时喂料A、B、C的剪切稀化指数分别为0.048，–0.869和–1.717；由温度与粘度的关系曲线可测算出剪切速率为11.07 s-1时，喂料A、B、C的粘流活化能分别为8.524、8.107和31.310 kJ·mol-1；经模拟计算可得在130 ℃和11.07 s-1速率下A、B、C 3种喂料的流动性指数分别为7.2×10-6，4.8×10-6， 1.1×10-6，A喂料的综合流变学性能最好。

Abstract:

For an optimized formula of the cementing agent good for formation, the viscosity and rheological properties of 93W-Ni-Fe PEM feeds with the same powder loading but four kinds of binder composition systems which were called A, B, C and D feedstocks were studied. By the British AR2000EX rotary rheometer, the viscosity of the tungsten-based alloy PEM feed at different shear rates and different temperatures were measured. The results indicate that among the four feedstocks, A has a low viscosity and good flow properties. The rheological properties of D feed are the most unstable. According to their relationship curves between viscosity and shear rate at the 130 oC, the shear-thinning index of A, B and C feeds can be calculated as 0.048, –0.869 and –1.717, respectively. According to the relationship curves between viscosity and temperature at the shear-rate of 11.07 s-1, the flow activation energy of A, B and C feeds can be calculated as 8.524, 8.107 and 31.310 kJ·mol-1, respectively. Through simulation, at 130 oC and the shear-rate of 11.07 s-1, the liquidity index of A, B and C feeds is 7.2×10-6, 4.8×10-6 and 1.1×10-6, respectively. The comprehensive rheological performance of A feed is the best.