Investigation of the effect of a TiN vacuum-plasma coating on the titanium alloy resistance to mechanical loading

• Published in: Metalurgija Vol. 45; no. 3; p. 206
• Main Authors: Gopkalo, A P, Rutkovskii, A V
• Format: Journal Article
• Language: English
• Published: 01-07-2006
• ISSN: 0543-5846

The results of experimental investigations into the static and cyclic strength of a VT20 titanium alloy with a TiN vacuum-plasma coating are presented. Application of a TiN vacuum-plasma coating increases the ultimate strength and yield strength by 6,5% and 17,37%, respectively, thus decreasing the relative elongation by 6,5% and relative reduction of area by 25,39%. The difference between the stresses at the end and at the beginning of the strain hardening region for coated specimens is 8,9 MPa, whereas for the initial material it is 134,7 MPa. Under the conditions of low-cycle stress-controlled loading TiN coatings increases the fatigue limit in the region of quasi-static fracture by 4,7%. In the region of fatigue fracture, the zone of transition from quasi-static to fatigue fracture is displaced into the region of shorter lives. In this case, an abrupt increase in the sensitivity of cyclic life to stress changes takes place (the susceptibility to brittle fracture increases).