A study on HVOF coatings of micron and nano WC-Co powders

被引：78

作者：

Cho, T. Y. ^{[1
]}

Yoon, J. H. ^{[1
]}

Kim, K. S. ^{[1
]}

Song, K. O. ^{[1
]}

Joo, Y. K. ^{[1
]}

Fang, W. ^{[1
]}

Zhang, S. H. ^{[1
]}

Youn, S. J. ^{[2
]}

Chun, H. G. ^{[3
]}

Hwang, S. Y. ^{[4
]}

机构：

[1] Changwon Natl Univ, Sch Nano Adv Mat Engn, Chang Won 641773, South Korea

[2] Sermatech Korea, Chang Won, South Korea

[3] Univ Ulsan, Sch Mat Sci & Engn, Ulsan, South Korea

[4] RIST, Minist Sci & Technol, 21st Century Frontier R&D Programs, Ctr Nanostructured Mat Technol, Pohang 790330, South Korea

来源：

SURFACE & COATINGS TECHNOLOGY | 2008年 / 202卷 / 22-23期

关键词：

HVOF coating; WC-Co powder; Hardness; Friction coefficient; Adhesive wear;

D O I：

10.1016/j.surfcoat.2008.06.106

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

High velocity oxy-fuel (HVOF) spray coating of micron (m) and nano (n) WC-Co powders has been studied for the improvement of durability of sliding machine components (SMC). In this work, optimal coating process (OCP) is obtained from the best surface properties of coating prepared by the Taguchi program. Hardness of coating is strongly dependent on powder size and spray parameters (SP) because of their strong influence on in-flight parameters. Hardness of n WC-Co is lower than that of m WC-Co since the degree of hard WC decomposition to less hard W2C, W and graphite is larger due to the larger specific surface area. Coating is porous since the decomposed graphite forms carbon oxide gasses by reaction with excess oxygen, and the gas evolution from coating makes porous coating. Porosity of n WC-Co coating is larger than that of m WC-Co because of larger evolution of carbon oxide gasses through n WC-Co coating. Friction coefficient (FC) is strongly dependent on the coating process (CP) since hardness and porosity of coating are dependent on the CP. FC of n WC-Co is lower than that of m WC-Co both at 25 degrees C and 500 degrees C, because of the more decomposition of n WC-Co. FC increases with increasing coating temperature (CT) from 25 degrees C to 500 degrees C both at in and n WC-Co because of the increase of adhesion by increasing surface temperature. WC-Co coating is very protective for the machine component since hardness of the coating is 2-3 times higher than those of machine component materials. Stick friction on WC-Co coating Surface occurs easily at higher temperature due to the higher FC at the higher temperature. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：5556 / 5559

页数：4

共 8 条

[1]

Adamson A W, 1982, PHYS CHEM SURFACES, P404

[2]

Cho T. Y., 2006, KOR SOC MACHINE TOOL, V15-6, P32

[3]

CHO TONG YUL, 2006, [Journal of The Korean Institute of Surface Engineering, 한국표면공학회지], V39, P240

[4]

CHO TY, 2006, 15 AER S LOG COMM RO

[5]

Cotton F. Albert, 1988, ADV INORG CHEM, P724

[6]

Davis JosephR., 2004, HDB THERMAL SPRAY TE

[7]

Massalski T.G., 1986, AM SOC METALS, V1, P600

[8]

SARTWELL BD, 1999, AESF EPA C ENV EXC, V231, P1

← 1 →