강체인 구와 DLC 코팅면 사이의 압입 및 미끄럼 접촉해석: 지지층 두께의 영향

Abstract

School of Mechanical Engineering, ERI, Gyeongsang National University(Received May 10, 2014 ; Revised June 24, 2014 ; Accepted June 25, 2014)Abstract − Various heat-treated and surface coating methods are used to mitigate abrasion in sliding machineparts. The most cost effective of these methods involves hard coatings such as diamond-like carbon (DLC). DLChas various advantages, including a high level of hardness, low coefficient of friction, and low wear rate. In prac-tice, a supporting layer is generally inserted between the DLC layer and the steel substrate to improve the loadcarrying capacity. In this study, an indentation and sliding contact problem involving a small, hard, spherical par-ticle and a DLC-coated steel surface is modeled and analyzed using a nonlinear finite element code, MARC, toinvestigate the influence of the supporting layer thickness on the coating characteristics and the related coatingfailure mechanisms. The results show that the amount of plastic deformation and the maximum principal stressdecrease with an increase in the supporting layer thickness. However, the probability of the high tensile stresswithin the coating layer causing a crack is greatly increased. Therefore, in the case of DLC coating with a sup-porting layer, fatigue wear can be another important cause of coating layer failure, together with the generallywell-known abrasive wear.Keywords − coating (코팅), DLC (Diamond-like carbon), supporting layer (지지층), sliding contact analysis (미끄럼접촉해석), abrasive wear (연삭 마멸), fatigue wear (피로 마멸)