Influence of compaction pressure and heating rate on tribological wear of sinters from Ti6Al4V powder manufactured by SPS

摘要

The Ti6Al4V alloy due to its characteristics is applicable not only in technology but also in medicine, such as porous implants and solid ones. In the case of solid implants, a major problem is inadequate tribological properties of this alloy and in order to improve them, new manufacturing techniques which include the method of spark plasma sintering are applied. The article presents the preliminary tribological results of sinters from Ti6Al4V powder produced by the SPS method. Sintering using an HP D 25-3 was carried out at 1000°C over 5 min at a compaction pressure of respectively 5, 25 and 50 MPa at a heating rate of 200,300 and 400 °C/min. The resulting sinters were measured for density and hard-ness, subjected to micro structure observations and friction and wear tests using the tribological tester T-05 (block-ring tribosystem) at tribosystem load for- ces of 120, 220 and 320 N. The tests were carried out at a constant speed of 0.36 m/s on a friction path of 1000 m. The dependence of the friction coefficient changes as a function of friction path as well as specified mass and volume wear of the tested materials is presented. Observations of the bearing surface morphology of the sinters were also conducted. It was shown that the sinters fabricated at a compaction pressure of 50 MPa and heating rate of 400°C/min demonstated the least tribological wear, and the main tribological wear mechanism was abrasive wear. On the bearing surface of the tested samples there were no signs of adhesive wear.