Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5464610 | Surface and Coatings Technology | 2017 | 7 Pages |
Abstract
The pre-heat treatment in vacuum rapid nitriding process was introduced to improve the surface hardening characteristics such as thick depth, high hardness and particularly to reduce the processing time. The pre-heat treatment was maintained for 30 min with an interval of 10 °C at the temperatures of 700- 800 °C under a high vacuum to allow the absorption of oxygen atoms on the titanium surface into the inner side. The following nitriding processes were equally performed at the same condition as 800 °C for 1 h. As a result, the depth of a hardened layer in the sample, which was treated at 800 °C for 1 h with the pre-heat treatment at 760 °C for 30 min, was similar to that of the treated sample at 800 °C for 3 h without pre-heat treatment and the depth was about 40 μm. The processing time can be largely reduced by introducing the pre-heat treatment process. The pre-heated specimens showed a longer wear lifetime by more than three times and higher friction resistance than that of PVD or non-nitrided specimens. The surface gradient-hardened layers exhibited excellent wear resistance and could prevent separation or debonding between matrix and the coated layer effectively.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
Hyeon-Gyeong Jeong, Yongtai Lee, Dong-Geun Lee,