稀土钕对粉末钛合金室温拉伸性能的影响

The Influence of the Rare-Earth Element Nd on the Room Tensile Properties of a PM Ti Alloy

摘要:

通过室温拉伸及扫描电镜(SEM)分析，研究了添加不同含量的稀土元素Nd对烧结态粉末钛合金的断口及力学性能的影响。结果表明，添加稀土元素可以有效改善粉末钛合金的室温塑性，使烧结态粉末钛合金室温延伸率达到21％，达到了熔断材水平。而且加入稀土后，在粉末钛合金中形成了稀土氧化物颗粒，颗粒尺寸小于5μm，在拉伸过程中，稀土氧化物断裂，起到了颗粒强化作用。添加0．8％～1．2％(质量分数)稀土钕可以得到室温综合性能优良的低成本粉末钛合金。

Abstract:

The mechanical properties, especially the elongation of the powder metallurgy (PM) Ti alloy (Ti12LC, Ti8LC) at room temperature are less than optimal due to oxygen contamination and porosity. The results of this work show that the addition of the rare earth element Nd to the PM Ti alloy resulted in improved tensile strength and elongation. The alloy containing 0.8wt% Nd has a tensile strength of 1 080MPa and an elongation of 14%. Almost the same as those of wrought material, while the processing cost was lower. The rare earth element served to scavenge oxygen from the powder surfaces thereby purifying the particle interfaces. This together with a decrease of the oxygen content of Ti substrate plus the formation of Nd oxides resulted in mechanical properties of PM Ti alloy.