Laser gas alloying of titanium - process technology and wear test results

To eliminate present difficulties at laser gas alloying of titanium as not sufficient control of nitrogen content, inadequate oxygen exclusion and pronounced crack formation tendency, a new technology was developed. It is based on a special copper made inert gas bell that ensures on-line controlled constant treatment parameters and reduced cooling velocity. So it is possible to adjust the properties of the laser gas alloyed layers. The thickness can be varied between 0.1 to 1.5 mm and the hardness can be adapted to the application in the range of 500 HV to 1200 HV. Such gas alloyed layers have very high resistance against abrasive and sliding wear. An additional hard amorphous carbon layer deposited by Laser-Arc technology on the gas alloyed layer can be used for achieving minimal friction coefficients in case of sliding wear. The gas alloyed layer can also be used for supporting other films like TiN to increase their bearing load. Results of fatigue tests of gas alloyed layers are presented as well as results of different wear tests.