The Effects of Ion Implantation on Friction and Wear of Metals.
Progress rept. Jan 80-Apr 81,
MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR MFG AND PRODUCTIVITY
Pagination or Media Count:
The effect of ion implantation on the friction and wear behavior of metals was investigated. Experiments were conducted with iron, titanium, and copper implanted with nitrogen ions, iron implanted with aluminum ions, and copper implanted with zinc ions. The significant reduction in friction and wear of the iron and titanium systems is attributed to a hard layer formed during the ion implantation process. This hard layer minimizes plowing and subsurface deformation and hence reduces the delamination wear process, i.e. crack nucleation, crack propagation, and the formation of delamination wear sheets. A finite element model of an elastic semi-infinite solid under the contact of a stationary rigid asperity showed that the hard layer does not change the subsurface stress distribution by supporting the load, but rather that this thin layer decreases the plowing component of friction. The model predicts that this decrease in the friction coefficient in turn, substantially reduces subsurface deformation and thus wear. The implanted copper specimens which did not appear to have a hard surface layer showed little improvement in their tribological behavior over the unimplanted copper.
- Metallurgy and Metallography