Interdiffusion behavior of Ni-Cr-Al-Y coatings deposited by arc-ion plating

Ni-Cr-Al-P coatings were deposited on the Ni3Al-base superalloys IC-6 and K 17 by are-ion plating. The results indicated that a small amount of substra te atoms, such as Co, Ti, Mo, etc., existed in the Ni-Cr-Al-Y coatings near the substrates, probably due to "sputter" and "antisputter." For the alloy K17, the impeding effect of Al was not obvious, because the temperatures o f the substrate and the coating were high (420-480 degreesC) during the dep osition process and interdiffusion was accelerated. However, for alloy IC-6 which contains Al, as well as a high concentration of Mo, the diffusion of Cr was impeded. Vacuum heat treatment at 1050 degreesC drastically increas ed diffusivities and the presence of Al and Mo was not enough to prevent so me Cr diffusion. Thus, the coating became mor e uniform and close to the de sired composition.