新型Ni-P功能梯度镀层的磨损特性研究

Wear Behavior of Electrodeposited Ni-PFunctionally Gradient Deposits

采用电沉积技术在钢表面制备了Ni-P功能梯度镀层和不同磷含量的Ni-P镀层,对比考察了2种镀层的磨损性能.结果表明: 沿镀层厚度方向,梯度合金镀层具有较好的成分和结构梯度;Ni-P梯度镀层的耐磨性较均质单层Ni-P镀层提高近1～2倍;经过高温热处理后,Ni-P合金镀层的主要磨损机制为裂纹萌生和扩展以及微区脆性剥落等,在磨损过程中梯度结构能够有效地抑制裂纹的萌生和扩展,从而使梯度结构合金镀层耐磨性大幅提高.

Ni-P functionally gradient deposits and Ni-P deposits with different P contents were deposited on steel substrates by electrodeposition method. The wear behaviour of two types of Ni-P deposits was investigated comparatively. Results indicated that the graded Ni-P deposits have better composition and structure gradients in the direction of thickness. After heat treatment, the wear resistance of Ni-P gradient deposit is 1-2 times higher than that of ungraded Ni-P deposits. Wear process of Ni-P deposits were characterized by micro-crack nucleation and propagation, brittle detachment. The formation and propagation of cracks within heat-treated Ni-P gradient deposits during the wear process were effectively inhibited due to the introduction of graded composition and structures and as a result, the wear resistance of Ni-P gradient deposits was improved greatly.