硬质合金表面SiC/DLC涂层组织和性能研究

Structure and Properties of Si C/DLC Coatings Deposited on WC-Co Cemented Carbides

DLC涂层可有效降低硬质合金刀具切削过程中的摩擦系数和切削力,使用等离子增强化学气相沉积的方法在硬质合金(YG8)基体和Si(100)表面沉积Si C/DLC涂层,其中,C_2H_2和H_2流量比分别为3∶0、2∶1、1∶1、1∶2和1∶3。测试了Si(100)表面Si C/DLC涂层的厚度、生长形貌、sp^3键的含量,并对硬质合金表面Si C/DLC涂层的硬度、膜基结合力和摩擦系数进行了全面分析。结果表明,Si C/DLC涂层均为非晶态形貌,随着H_2流量的增加,涂层厚度不断下降;当C_2H_2/H_2=1∶1时,涂层的sp^3键的比例最大,并达到41.0%,且具有较低的摩擦系数;涂层的硬度和弹性模量随着H2流量的增加而降低;C_2H_2/H_2=1∶3时,涂层表现出最佳的膜基结合力。

DLC coatings are used to decrease the friction coefficient and cutting force during machining. In this paper,Si C/DLC coatings were deposited on WC-Co cemented carbides（ YG8） and Si（ 100） substrates by a PECVD method,during which C2 H2/H2 ratios under 3∶0,2∶1,1 ∶1,1 ∶2 and 1 ∶3 were introduced into the chamber. The thickness,morphology,sp3 content,hardness,adhesion and friction coefficient of the as-deposited coatings were tested,respectively. As a result,all DLC coatings showed amorphous morphology,however,the thickness of the coatings decreased with H2 flow ratio increased. The sp3 content was tested to reach 41. 0% when the C2 H2/H2 was 1 ∶1,and the low friction coefficient was found. The hardness and elastic modulus decreased with H2 flow ratio increased. The coating showed best adhesion under the flow ratio of C2 H2/H2= 1∶3.