Study On The Process And Properties Of Titanium And Titanium Alloy Boriding

TC4 Titanium alloy is a typical two-phase ?+? type titanium alloy, Which contains 6% of the a-phase stabilizing elements aluminum and 4%vanadium ? stabilizing element.Due to the titanium alloy has properties of high strength,low elastic modulus, good corrosion resistance and heat resistance, It has been applied in a wide ranges in the aerospace industry.However, with the development of society and economy, titanium alloy also exposed many shortcomings in real situations, Such as low hardness, poor wear resistance and fretting corrosion.The experiments apply the two different method, solid powder method and paste method to do the bronzing the TC4 titanium alloy. To determine boronizing parameters (Temperature,Time, Adding quantitative rare earth) and study the different process influence on the diffusion layer properties.For powder method, selecting at 900?,1000?,1100? three temperatures as boronizing temperature, selecting 10h,12h,14h for three kinds of holding time for holding time.By the morphology and characteristic analysis, on the temperature is 1100?, keeping temperature time is 12h by incubation conditions, The TiB2 layer has a hard phase formation that can be found.Do heat treatment at 850?950? by paste method for TC4 titanium alloy Selecting for the respective highest temperature is 850??900??950?.Keeping temperature time is 10h? 12h?14h.With the best Boronizing rare plus diffusion layer thickening is in the optimization of the highest temperature at 950? and keeping temperature time is 10h.Based on the above, the process parameters were set for TC4 titanium alloys paste method and boronizing treatment method. The optimization process parameter is highest temperature at 950?, holding temperature for 10h.XRD analysis shows that the intermediate compound TiB discoveried in the infiltration layer TiB and with the added rare earth content increased,The content of TiB increases significantly.Layer hardness increases 80% and the wear resistance increases 30% after a single boronizing; The layer hardness increases 85% and wear hesitance increases 50% after diffused bornonizing and rare earth element together.