高纯金属钒粉烧结性能研究

利用电子探针观察高纯金属钒粉粒度和形貌, 使用油压机将高纯金属钒粉压制成坯条, 并采用万能试验机测定钒坯条压溃变形力曲线, 分析钒坯条最优压制压力; 分别通过热压烧结和冷等静压+真空烧结的方法对高纯钒粉进行烧结, 研究烧结工艺对高纯钒粉烧结特性和力学性能的影响。结果表明: 采用冷等静压+真空烧结的方法, 在压制成形过程中, 钒粉压坯密度和相对密度随压力的增加而逐步提高, 压力提高到280 MPa时, 压坯密度和相对密度分别为3.99 g·cm-3和66.94%;经真空烧结后, 坯料密度和相对密度分别为5.28 g·cm-3和88.59%。压制压力由80 MPa提高到200 MPa时, 压溃强度从0.4 MPa增加到6.0 MPa, 增大趋势较为明显; 压制压力提高到280 MPa时, 压溃强度增加到7.4 MPa, 增大趋势变缓。经热压烧结坯料的相对密度比冷等静压+真空烧结坯料的相对密度高, 280MPa压力下热压烧结坯料密度和相对密度分别达到5.51g·cm-3和92.91%。

Research on sintering performance of high purity metal vanadium powders

The grain size and morphology of high purity metal vanadium powders were observed by electron probe, the vanadium billets were pressed by oil hydraulic press, and the crushing force curves were measured by the universal machine to study the optimum pressing pressure for vanadium billets. Then, the high purity vanadium powders were treated by hot pressing sintering and cold isostatic pressing + vacuum sintering, respectively, to study the effect of sintering process on the sintering performance and mechanical property of vanadium powder products. The results show that, in the cold isostatic pressing with vacuum sintering process, the density of raw compact increases with the increase of pressing pressure. When the pressure increases to 280 MPa, the density and relative density of raw compacts are 3.99 g·cm-3 and 66.94%, respectively, and the density and relative density of products after vacuum sintering are 5.28 g·cm-3 and 88.59%, respectively. With the pressure increasing from 80 MPa to 200 MPa, the compressive strength increases significantly from 0.4 MPa to 6.0 MPa; when the pressure increases to 280 MPa, the compressive strength slowly increases to 7.4 MPa. The relative density of products by hot pressing sintering is higher than that by cold isostatic pressing + vacuum sintering, and the density and relative density of products by hot pressing sintering at 280 MPa reach to 5.51 g·cm-3 and 92.91%, respectively.