电弧离子镀法制备高硬度Cr-Si-C-N薄膜

Cr-Si-C-N HARD FILMS PREPARED BY ARC ION DEPOSITION METHOD

采用电弧离子反应沉积技术在SCM415渗碳淬火钢基片上沉积了Cr-Si-C-N薄膜,三甲基硅烷(TMS)反应气体作为Si和C掺杂源,通过改变TMS流量实现了薄膜中Si和C含量的调节.利用XPS,XRD,HRTEM和显微硬度计研究了Cr-Si-C-N薄膜的化学状态、显微组织和显微硬度.Cr-Si-C-N薄膜中的Si和C含量随TMS流量的增加而单调增加.在TMS流量小于90 mL/min时,薄膜中Si和C含量较少,薄膜由Cr(C,N)纳米晶与Si_3N_4非晶(nc-Cr(C,N)/a Si_3N_4)组成,薄膜硬度随流量的增加而单调增大,最大至4500 HK.硬度的增加源于固溶强化及薄膜中纳米晶/非晶复合结构的形成;当TMS流量大于90 mL/min时,薄膜中Si和C含量较多,多余的C以游离态形式存在,且随TMS流量的增加而增多,薄膜硬度下降.

PVD or CVD Me-Si N nanocomposite films synthesized by doping Si element in metallic nitride matrix have exhibited good oxidation resistance and wear resistance. As melting the alloy target containing Si is not easy, it is difficulty to dope much more Si in the films by PVD techniques. In addition, the Me-Si-N films do not have enough lubrication. In this paper, Cr-Si-C-N films were prepared by cathode arc ion deposition technique, in which tetramethylsilane （TMS） was used as Si and C sources, and their concentrations in the Cr Si-C N films can be controlled by TMS flow. The state of chemical bonding, microstructure and microhardness were investigated by XPS, XRD, HRTEM and microindentation hardness tester. Results show that the Si and C contents increase monotonicly with the increase of TMS flow. When the TMS flow is lower than 90 mL/min, the Cr Si-C-N film has a composite structure of Cr（C, N） nanocrystals dispersing in the amorphous Si3N4 （nc-Cr（C, N）/a-Si3N4）, and the microhardness increases to 4500 HK with increasing TMS flow. Such high hardness originates from the solid solution hardening of the doping fewer element and the Veprek nanocomposite structure hardening mechanism. With the further increase of TMS flow, the hardness decreases because of the appearance of free C.