Modification of surface morphology to enhance tribological properties for CVD coated cutting tools through wet micro-blasting post-process

Abstract

Coated cemented carbide tools have been widely applied in high performance machining due to their excellent heat resistance and anti-wear properties. However, as-deposited tool coatings are still challenged by the growing requirements to further enhance cutting performance. Wet micro-blasting post-process on coating tools has been proposed to improve mechanical properties and increase tool life. This paper aims to optimize the wet micro-blasting operating parameters for chemical vapor deposition (CVD) coated tools to strengthen their wear resistance. The surface morphology of three types of CVD coated tools including TiN/Al2O3/TiCN, thin Al2O3/TiCN and thick Al2O3/TiCN are inspected with EDS, SEM and AFM. Tribological properties for both as-deposited and wet micro-blasted tool coatings were evaluated by dry reciprocating sliding tests. The measured results indicate that the wet micro-blasting process can significantly decrease the surface roughness and improve the wear resistance. Among the wet micro-blasting operating parameters, the wet micro-blasting time and the abrasive particle size are found to play more important roles in the formatting of top surface morphology and the enhancement of the tribological behavior than the role played by blasting pressure. Based on the research results, the CVD tool coatings with improved anti-wear properties and surface topography can be fabricated with suitable wet micro-blasting process parameters.