http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
구본우(B. W. Gu),권혁우(H. W. Kwon),김용석(Y. S. Kim) 한국소성가공학회 2016 한국소성가공학회 학술대회 논문집 Vol.2016 No.4
During the sling wear of a ferrous metal, a subsurface layer is formed of which the microstructure, constituting phases and the mechanical property are different from those of the original wearing metal. Since the wear occurs at the layer, it is important to understand how the wear rate varies with different layers. The layers are composed of oxide layers, MMLs and deformation layers. Their formation mechanisms are known to vary depending on sliding-wear test conditions such as counterpart material and environmental conditions. In this research, two different counterparts, AISI 52100 steel and Al₂O₃ were utilized to see the effect of counterpart on the formation of the layers and subsequent wear behavior. Sliding wear tests of the pure iron were carried out to exclude other effects from the carbide and cementite phases in the air and in an Ar atmosphere. After the sliding wear test, worn surfaces, debris and cross sections were analyzed by SEM, TEM and EDS. Wear rates were analyzed by comparing constituting phases, mechanical properties and thickness of the layer, which changed with the two different counterparts and test environments.
권혁우(H. Gwon),허하리(H. L. Hur),구본우(B. W. Gu),김종국(J. K. Kim),강용진(Y. J. Kang),김용석(Y. -S. Kim) 한국소성가공학회 2015 한국소성가공학회 학술대회 논문집 Vol.2015 No.10
Tribological characteristics of a-C:H coating and ta-C coating against AZ31 Mg alloy was investigated. The a-C:H coating was deposited on a STD-61 steel pin by the plasma-enhanced chemical-vapor deposition (PECVD) process. The hydrogen-free DLC (ta-C) was prepared by filtered vacuum arc deposition (FCVA). Dry sliding friction and galling characteristics of the two DLC coatings on the STD-61 steel against AZ31 Mg alloy disks were evaluated using a reciprocating sliding tribometer at room temperature and at 250 ℃. To represent a real sliding during the sheet metal forming process, single-stroke tests were adapted (10 mm of stroke length) rather than a reciprocating long sliding-distance test. Both a-C:H coating and ta-C coating suppressed the adhesion between the Mg alloy and the tool steel at room temperature, which kept the friction coefficient low. However, at 250 ℃, both DLC coatings exhibited severe adhesion to the Mg alloy, which increased the friction coefficient and the galling.