水热法和氢气还原法制备纳米Mo–40Cu复合粉末及其烧结性能研究

Study on sintering properties of nano Mo–40Cu composite powders prepared by hydrothermal method and hydrogen reduction method

结合水热法和氢气还原法制备纳米Mo–40Cu复合粉末,利用X射线衍射仪、扫描电子显微镜、透射电镜等手段研究了氢气气氛下烧结工艺对Mo–40Cu复合材料组织和力学性能的影响。结果表明,最佳制粉工艺为水热温度400℃和氢气还原温度700℃,获得了均匀的Mo–40Cu复合粉末,粉末粒径为70~90 nm;在氢气气氛下最佳烧结工艺为1300℃保温2 h,合金的相对密度、抗弯强度、硬度、电导率和热导率分别为98.1%、1060 MPa、HRA 51、20.8 MS·m-1和191.7 W·m-1·K-1,热膨胀系数在500~700℃约为10.8×10-6 K-1,合金中组织均匀,晶粒细小,尺寸约为3~4μm。

The Mo–40Cu composite powders were prepared by the hydrothermal and hydrogen reduction method,the effects of sintering process in the hydrogen atmosphere on the microstructure and mechanical properties of the Mo–40Cu composites were studied by X-ray diffraction (XRD),scanning electron microscope (SEM),and transmission electron microscope (TEM).The results show that,the optimum process parameters for the powder preparation are 400℃for the hydrothermal temperature and 700℃for the hydrogen reduction temperature,obtaining the homogeneous Mo–40Cu composite powders with the powder particle size of 70~90 nm.The optimum sintering process in the hydrogen atmosphere is sintering at 1300℃ for 2 h,the relative density,bending strength,hardness,electrical conductivity,and thermal conductivity are 98.1%,1060 MPa,HRA 51,20.8 MS·m-1,and 191.7 W·m-1·K-1,respectively,and the thermal expansion coefficient is 10.8×10-6 K-1 at 500~700℃.The microstructure of Mo–40Cu alloy is homogenous with the grain size of about 3~4μm.