氩气氛环境下真空阴极弧制备ta-C涂层电弧电流效应

Effect of arc current on ta-C coatings deposited by vacuum cathodic arc at argon atmosphere

利用真空阴极弧技术在M2高速钢和单晶硅表面沉积ta-C薄膜,重点研究了电弧电流对沉积过程中等离子体行为,以及涂层的截面形貌、厚度、结构和膜-基结合强度的影响。结果表明,随着电弧电流从40A增加到100A,基体电流由1.36A增加到3.95A,等离子体中Ar离子数目的增加速率高于C离子。随着电弧电流由40A增加到60A,涂层沉积速率基本不变约为6nm/min。在这一过程中,电子对Ar的离化所导致对涂层的轰击溅射效应优于C离子/原子在沉积过程中的传递效应,因此弧流增加而沉积速率基本不变。随着弧流由60A继续增加到100A以后,C离子/原子在沉积过程中的传递效应导致沉积速率提高优于Ar离子的溅射作用,因此沉积速率增加到8.1nm/min。电弧电流为80A时,I_D/I_G比值最小为0.31,表明涂层具有最高的sp^3含量。因此,在Ar气氛下制备ta-C涂层时,要得到较优质的ta-C涂层,需要合适的弧流。制备涂层的膜-基结合强度最高可达HF 1,可进行工业应用。

The ta-C coatings were deposited on HSS（M2） and single-crystal Si using vacuum cathodic arc. The effect of arc currents on the plasma characterization, fracture morphology, coating thickness, coating structure and adhesion strength was investigated. The substrate current increased from 1.36A to 3.95A as the arc current increased from 40A to 100A. The increment speed was higher for argon ions than that of carbon ions in plasma. The deposition rate was almost keep constant of 6 nm/min as the arc current increased to 60A, which may attribute to the sputtering effect by argon ions induced by increased amount of electrons, then increased to 8.1 nm/min as the arc current increased to 100A, which may attribute to the improved amount of carbon ions/atoms. The arc current of 80A led to the smallest ID/IG（0.31）, which means the highest sp3 content. A proper arc current employed higher quality of the ta-C coatings at argon atmosphere. The ta-C coatings showed high quality of adhesion strength（highest of HF 1）, which could be utilized in industrial field.