Wear performance of selective laser melted Ti-6Al-4V alloy in situ modified with oxygen and boron

Abstract

Titanium alloys have poor wear performance, with severe adhesive wear and three-body abrasion being dominant mechanisms. To extend the use of titanium to applications demanding better wear properties, modifications can be made to the alloys. This can include the addition of hard particulates or interstitial strengthening, by increasing the oxygen or nitrogen content. The metal additive manufacturing process of selective laser melting (SLM) has been shown to enable manufacture of these modified titanium alloys in situ. In this study, small amounts of boron and titanium dioxide powders were added to Ti-6Al-4V (Ti64) and processed using SLM. To compare wear performance of these modified materials, reciprocating pin on plate tests in brine solution were performed. Increased oxygen content increased the hardness of the material, which reduced wear. The presence of boron increased wear in the short term but reduced the long-term wear rate. Incorporating of oxygen and boron has been shown to improve the saline solution wear properties of Ti64 against silicon nitride.