Optical in-situ observation and analysis of macro and micro characteristics of lubrication layers with different powder thickness
KONG Junchao1，WANG Gang2，DONG Huifang1，CHEN Yuxiang1，NIU Tianliang1，
MENG Xiangcheng1
（1.College of Mechanical Engineering, Chaohu College, Hefei 238000,China; 2. Institute of Tribology, Hefei
University of Technology, Hefei 230009, China）
Abstract：Based on the linear reciprocating in-situ observation tester, the effects of powder layer thickness on interface
wear condition, friction characteristics and real contact area ratio in 30 strokes were analyzed. The results
show that thickness of powder layer is 1.5 μm, the powder layer is relatively thin on the surface of specimen. Asperities
in some areas is initially exposed, and powder lubrication film is not formed. Main load is the contact load of
asperities and serious wear marks appear. The initial real contact area ratio is 11.17% and finally decreases to
20.14%. The powder layer is 4.5 μm that the good lubrication film is formed in the area completely covered by the
powder layer, and finally the lubrication film is completely peeling off and load is reduced. The powder layer is
6μm that powder layer completely covers the contact area and form complete lubrication film, load of powder layer
is dominant and there is no scratch. Load first increases to 6 N and then decreases to 2 N, and asperities bearing capacity
2 N accounts for 33% of the total load. Friction ratio of powder layer is more than 73.3% and the real contact
area ratio remains above 60%. The results shows that powder layer thickness is 6 μm that the powder has good flatness, high carbon content, full contact and good lubrication.
2024, Vol. 34 
