喷丸预处理对Ti6Al4V合金低温等离子体氮化的影响

Effect of Shot Peening Pretreatment on Low Temperature Plasma Nitriding of Ti6Al4V Alloy

摘要:

为改善钛合金表面耐磨性能，同时达到防止薄壁零部件变形和节约能源的目的，以Ti6Al4V钛合金为对象，研究了喷丸强化预处理对钛合金低温渗氮层及耐磨性的改善作用。结果表明，喷丸强化预处理能够有效促进钛合金表面低温离子渗氮过程，在500 ℃低温渗氮试验条件下，随着喷丸预处理强度的增大，钛合金渗氮效率逐步提高，渗氮层的表面硬度、承载能力和表观韧性逐步增加，使得渗氮层的耐磨性能逐步提高。当喷丸预处理强度增加到0.25 mmA时，Ti6Al4V钛合金渗氮层的表面硬度比单纯渗氮处理试样提高32.7%，磨损率降低42.3%，使钛合金基体的磨损率降低70.5%，较好地实现了喷丸预处理促进钛合金低温离子渗氮的目标。

Abstract:

In order to improve the wear resistance of titanium alloy, and to prevent the deformation of thin-walled components, taking Ti6Al4V alloy as the object, the effect of shot peening pretreatment on the low-temperature nitriding of titanium alloy was studied. The results show that the pretreatment of shot peening (SP) can effectively promote the plasma nitriding process at low temperature. Under the test conditions of 500 °C, with the increase of shot peening strength, nitriding efficiency of pretreated samples increases gradually, and the surface hardness, load-bearing capacity and the wear resistance of nitrided layer increase gradually. Compared with unpretreated nitrided samples (Ti6Al4V-PN), when the shot strength increases to 0.25 mmA, the surface hardness of the pretreated nitrided samples (SP(0.25)-PN) increases by 32.7% and the wear rate decreases by 42.3%. The goal of shot peening pretreatment to promote low-temperature plasma nitriding of Ti6Al4V alloy is well achieved.