Study On The IBAD Coatings On The Surface Of Titanium Alloy And Its Fretting Fatigue Behavior At High Temperature

Fretting fatigue (abbreviated as FF) is an important failure way of Compressor Blade Tenon made from titanium alloy, thus it affects reliability of engine. However, there are no effective measures to slove the FF problem of titanium alloy blade at high temperature now, for its complication and so many influencing factors. Coating and surface modification technology is very promising technology approaching fretting fatigue. To slove the FF problem of titanium alloy at high temperature, the ion-beam assisted deposition (IBAD) technology was applied to prepare the anti-wear coating on the surface of titanium alloy, and the process of coating, the evaluation of coating basic property and tribology behavior were also investigated. On the basis of aboved work, the influencing principles of ion beam assisted deposition coating and duplex treatment coating which combines shot peening (SP) with IBAD technology were studied, and their mechanism was investigated to provide guide to new ways of controling FF damage of titanium alloy at high temperature. The main contributions are as follows:(1) On the basis of optimizeing processes, the excellent adhesive strength, denser and tenacious coatings (including IBAD TiN/Ti, IBAD 0Cr18Ni9, IBAD NiCr20 andIBAD Al) were prepared, while the soft Al coating with good lubrication and outstanding anti-friction property was also acquired. The hard TiN coating with good wear resistance significantly improve wear property of titanium alloy.The hardness of 0Cr18Ni9 and NiCr20 coatings are significantly higher than bar material, and they have a certain improvement in the wear resistance of titanium alloy, although they can't reduce coefficient of friction.(2) The effect of IBAD coatings which include TiN/Ti, 0Cr18Ni9, NiCr20 and Al on the FF behavior of titanium alloy were studied. It was founded that the hard TiN/Ti coating significantly improves fretting fatigue life of titanium alloy at 350℃, because of the good tenacity of coating and excellent lubrication of Ti partiles.The soft Al coating with good tribology and lubrication has greatly prolonged the FF life of itanium alloy. NiCr20 and 0Cr18Ni9 coatings have no obvious effect on the FF of titanium alloy at elevated temperature.(3) The effect of the duplex treatment technology which combines SP with IBAD...