低温自蔓燃和还原法制备纳米Mo-30Cu复合粉末及其烧结性能

Preparation of Nano Mo-30Cu Composite Powders by Low Temperature Self-Propagating and Reduction Method and Their Sintering Properties

Mo-Cu合金具有高电导率、高热导率、低膨胀率等优点,被广泛应用于电子封装材料、热沉材料、集成电路散热元件等领域。本实验以硝酸铜、钼酸铵、葡萄糖和尿素为原料,采用低温自蔓燃法获得Mo-30Cu合金的前驱体粉末,然后在氢气气氛下还原制备纳米Mo-30Cu合金粉末。采用XRD衍射仪和扫描电镜研究了硝酸铜和尿素、硝酸铜和葡萄糖不同物质的量比对Mo-30Cu合金前驱体粉末和还原粉末物相、形貌和性能的影响,探讨了不同烧结温度下Mo-30Cu合金的力学性能和物理性能。实验结果表明,硝酸铜和尿素、硝酸铜和葡萄糖的最佳物质的量比分别为1∶2和1∶0.3,还原粉末细小均匀,平均粒径约为70 nm,两相分布均匀。氢气气氛下在1300℃烧结2 h所制备合金的致密度、抗弯强度、硬度、电导率、热导率和热膨胀系数分别为98.3%、1022 MPa、221HV、22 MS/m、195 W·m-1·K-1和10.5×10-6 K-1。合金组织细小均匀,Mo、Cu两相分布均匀,断裂方式为韧性断裂。

Mo-Cu alloys have the advantages of high conductivity and thermal conductivity,low expansion rate,etc.They were widely used in electro-nic packaging materials,heat sink materials,integrated circuit heat-dissipation components and other fields.Using copper nitrate,ammo-nium molybdate,glucose and urea as raw material,nano Mo-30Cu composite powders were prepared by low-temperature self-propagating and reduction method.Subsequently,different copper nitrate and urea,glucose ratio precursor powder and powder after reduction were characterized by XRD and SEM.The effect of sintering process on microstructure and properties of Mo-30Cu alloy was investigated.The results showed that the best mole ratio of copper nitrate to urea and glucose is 1∶2 and 1∶0.3,respectively.Mo-30Cu composite powders were fine and uniform,and Mo and Cu phases are evenly distributed,and the average diameter of powders is about 70 nm.The best sintering process is at 1300℃for 2 h.The alloy had a density of 98.3%,a bending strength of 1022 MPa,a hardness of 221HV,a electrical conductivity of 22 MS/m,a thermal conductivity of 195 W·m-1·K-1,and a thermal expansion coefficient of 10.5×10-6 K-1.The microstructure is fine and uniform,and Mo and Cu are even.The fracture morphology showed ductile fracture.