高级检索

纳米W-30Cu-La2O3粉末的制备及其烧结性能

Preparation and Sintering Properties of Nanometer W-30Cu-La2O3 Composite Powder

  • 摘要: 钨铜合金具有高强度、良好的耐磨性和优异的高温导电性,广泛用于电子封装和高压电接触材料等领域。本文以钨酸、硝酸铜、六水硝酸镧为原料,甘氨酸为燃料,硝酸铵为助燃剂,采用低温自蔓燃法制备前驱体粉末,经氢气还原获得纳米复合粉末,烧结制备W-30Cu-La2O3合金。利用XRD和SEM研究钨酸与甘氨酸、硝酸铵的摩尔比对前驱体粉末和复合粉末物相、形貌和性能的影响,分析不同烧结温度下W-30Cu-La2O3合金的致密度、微观组织和综合性能。结果表明,钨酸与甘氨酸、硝酸铵的摩尔比分别为1:10、1:25时,粉末均匀性好,比表面积为6.6271 m2·g-1,粉末尺寸为100~200 nm。在1350 ℃烧结制备的合金致密度、抗弯强度、维氏硬度和热膨胀系数分别为99.0 %、1205 MPa、307 HV和9.17×10-6 K-1,组织细小均匀,断裂方式为韧性断裂。

     

    Abstract: Tungsten copper alloy has high strength, good wear resistance and excellent high-temperature conductivity, and is widely used in electronic packaging and high-voltage electrical contact materials. Tungsten copper oxide precursor powder was prepared by low temperature self-propagation method with tungstic acid, copper nitrate, cerium nitrate hexahydrate as raw materials, glycine as fuel, ammonium nitrate as accelerant. Nano-tungsten copper composite powder was obtained by hydrogen reduction, and W-30Cu-La2O3 alloy was prepared by sintering. The effects of different molar ratios of tungstate, glycine and ammonium nitrate on phase, morphology and properties of precursor powder and composite powder were investigated by XRD and SEM. The density, microstructure and comprehensive properties of W-30Cu-La2O3 alloy at different sintering temperatures were analyzed. The experimental results show that the optimal molar ratio of tungstic acid to glycine and ammonium nitrate was 1:10 and 1:25, respectively. The powders have good uniformity, the specific surface area is 6.6271 m2·g-1, and the powder size is 100~200 nm. The density, bending strength, Vickers hardnesses, and coefficient of thermal expansion of the alloy sintered at 1350℃ are 99.0%, 1205MPa, 307HV, and 9.17×10-6 K-1, respectively. The microstructure is fine and uniform, and the fracture morphology is ductile.

     

/

返回文章
返回