烧结温度对W-40vol.%ZrC性能与组织的影响

Effect of sintering temperature on microstructure and properties of W-40vol%ZrC

摘要:

采用放电等离子烧结(SPS)和常压氢气烧结制备了W-40vol.%ZrC的复合材料,研究了烧结温度对其密度、力学性能和微观组织的影响。结果表明,采用SPS烧结能在低于常压氢气烧结200℃下,实现W-40vol.%ZrC的高相对密度和高强度和细晶组织。采用SPS烧结在1600℃时的相对密度、硬度和抗弯强度分别达到为98.56%、HRA78.1和501MPa,W和ZrC的平均晶粒度分别为3μm和1.5μm；而采用常压氢气烧结在1860℃烧结时达到最优值,其相对密度、硬度和抗弯强度达到98.95%、HRA77.3和726MPa,W和ZrC的平均晶粒度分别为10μm和4.5μm。微观组织分析显示SPS烧结较常压氢气烧结制备W-40vol.%ZrC的ZrC相分布更加均匀细小,其能减少材料变形中由于ZrC团聚造成应力集中而引发的脆性断裂。

Abstract:

W-40vol%ZrC composites was prepared by spark plasma sintering (SPS) and ordinary consolidation sintering respectively. The relative density, mechanical properties and microstructure were studied. The resules show that high relative density, high strength and fine grains structure can be achieved by SPS which is reduced 200℃ to the ordinary consolidation sintering. The relative density, hardness, bending strength of W-40vol%ZrC composites sintering at 1600℃ was 98.56%, HRA78.1 and 501MPa respectively. The average grain sizes of W and ZrC was 3μm and 1.5μm. O-W40ZrC had the optimun value sintering at 1860℃, the relative of density, hardness and bending strength was 98.95%, HRA77.3 and 726MPa. The average grain sizes of W and ZrC was 10μm and 4.5μm. Compared with ordinary consolidation sintering, the tungsten grain is more fine and ZrC particles is much more well-distributed prepared by spark plasma sintering, and the fine grains has a beneficical effect on fracture process.