ZrC对等离子喷涂成形钼制品的影响

Influence of Zirconium Carbide on Properties of Molybdenum Products Produced by Plasma Spray Forming

采用包覆法制备了Mo-ZrC复合粉末,采用等离子喷涂成形,再对其进行热等静压处理得到复合材料零部件。将其与纯钼粉末等离子喷涂成形零部件作对比。用阿基米德法测量两种零部件的相对密度;用显微硬度计测量它们的维氏硬度;用万能材料试验机测试它们的拉伸强度;用扫描电镜观察它们的截面和拉伸断口微观形貌。结果表明,加入的ZrC在基体中呈弥散分布,且分布均匀,填充了钼颗粒之间的部分空隙。纯钼材料拉伸断口呈沿晶断裂,而复合材料的拉伸断口出现了部分穿晶解理断裂。纯钼材料的相对密度为86.5%,拉伸强度及显微硬度都较低。而复合材料的相对密度为89.7%,力学性能有显著提高,拉伸强度提高到123 MPa,显微硬度提高到275 HV0.025。

Mo-ZrC composite powder was fabricated by coating method.Composite parts were produced by plasma spray forming(PSF) and hot-isostatic pressing(HIP).Comparing these parts with the one produced by pure molybdenum powder.The relative density,micro-hardness and tensile strength of composite parts were investigated.Cross section and fracture of these products were observed by scanning electron microscope(SEM).The results showed that the ZrC was dispersed in the matrix,was evenly distributed,and partially fill the gap between the molybdenum particles.Pure molybdenum tensile fracture was intergranular fracture,and the transgranular rupture could be found in its fracture surface.The relative density of pure molybdenum materials was 86.5%,with low tensile strength and microhardness.And the relative density of the composite parts was 89.7%.The mechanical properties were significantly improved.The tensile strength was increased to 123 MPa,and microhardness was increased to 275 HV0.025.