磁控溅射制备内燃机用Ti600合金表面CrN/NbN涂层的性能表征分析

为了提高内燃机用Ti600合金表面性能,通过脉冲磁控溅射的方式在其表面制备CrN/NbN涂层,分析了涂层组织结构与电压、占空比的关系。研究结果表明:在CrN/NbN涂层内形成了许多柱状外形的组织成分,并且当占空比以及电压提高后,形成了致密度更大的CrN/NbN涂层。厚度随着占空比和电压的增加表现出明显的增加规律,在占空比10μs和电压400 V时,涂层厚度最大值12μm左右。随着占空比和电压的增加,硬度和弹性模量均表现出单调增加。在占空比10μs和电压400 V时,涂层硬度和弹性模量达到最大值,分别为35.6和31.7 GPa。随着占空比增加,残余应力表现出单调减小;随着电压的增加,残余应力表现出先减小后增加,最小值发生在电压380 V时。各涂层试样都产生了具有完整结构的压痕,没有发生膜与基体剥离的情况。随着占空比和电压进一步增大,在试样的压痕边缘部位产生环状分布的裂纹。

Surface Modification of Ti600 Alloy with CrN/NbN Coatings: An Experimental Study

The surfaces of Ti600 alloy,an advanced material for internal combustion engine,were modified with CrN/NbN coatings deposited by high power impulse magnetron sputtering(HiPMS).The influence of the voltage and duty-cycle on the microstructures and tribological behavior was investigated.The results show that the voltage and duty-cycle has a major impact.To be specific,the columnar-phased grains dominated,and as the voltage and duty-cycle increased,the thickness,compactness,hardness,and elastic modulus of the CrN/NbN coatings increased; deposited at 400 V and a duty-cycle of 10 μs,the coatings with strong interfacial adhesion had the max-thickness of 12 μm,max-hardness of 35.6 GPa,max-elastic modulus of 31.7 GPa.The residual stress decreased(changed in a decrease-increase mode) with an increase of duty-cycle(the voltage),the indentation produced ring-shaped cracks at the edges on the coatings,synthesized at a voltage higher than 400 V and a duty-cycle longer than10 μs.