钼铜复合粉末的致密化及性能

对微波辅助法制备的钼铜复合粉末进行压制烧结,研究其致密化行为及复合材料性能。结果表明:烧结温度是控制钼铜复合材料成分、微观组织及综合性能的关键因素。1100℃下烧结的钼铜复合材料Cu含量最接近设计含量,过高的烧结温度将引起铜的损耗。在较低的烧结温度下(≤1100℃),复合材料的力学性能和物理性能随温度的升高而升高,但是过高的烧结温度(1200℃)会引起铜相的大量损失及颗粒异常长大,从而导致复合材料密度、硬度、导电率及导热率的降低。通过优化实验参数,1100℃下的复合材料具有理想的微观结构,铜相损失较少,复合材料成分接近设计成分,钼铜两相分散较为均匀,力学性能及物理性能优异,复合材料的密度、硬度、抗弯强度、电导率及热导率分别为9.79g/cm^3,229.1HV,837.76MPa,24.97×10~6S·m^-1和176.57W·m^-1·K^-1。

Densification and properties of Mo-Cu composite powders

The Mo-Cu nano-powders were synthesized by a microwave-assisted aqueous solution strategy and subsequent low-temperature hydrogen reduction process.The sintering densification behavior of Mo-Cu composite powders and the sintering properties of the composite compacts were investigated.Results show that the sintering temperature is a critical factor in the densification process of Mo-Cu composites.The shrinkage rate,density and hardness of sintered composites increase as the temperature rises.However,too high sintering temperature causes significant loss of copper phase and abnormal grain growth,resulting in decrease in density,hardness,electrical conductivity and thermal conductivity.By optimizing all the performance indicators,high performance Mo-25%Cu composites with homogeneous microstructure accompanied with good physical and mechanical properties can be obtained by sintering for 2h at 1100℃,for the actual chemical composition is highly close to the designed chemical composition.The density,hardness,bending strength,electrical conductivity and thermal conductivity are 9.79g/cm^3,229.1HV,837.76MPa,24.97×10^6S·m^-1 and 176.57W·m^-1·K^-1,respectively.