Optimization Of Ultrasonic Surface Rolling Process Equipment And Its Effect On Solid Particles Erosion Performance Of Ti-6Al-4V

Titanium alloys thanks to their low density,high specific strength and excellent overall performance are considered very important raw materials in the aerospace industry.In particular,Ti-6Al-4V is the dominant material for rabbet manufacturing of aircraft engines.During the service of the aircraft,small sand and dust particles enter into the engine chamber along with the airflow,and impact the surface of the rabbet at high speed,which ultimately results in surface destruction.The wear resistance of titanium alloy is poor,which makes erosion wear become one of the main damage forms of the final stage blades of aircraft engines during service.In this paper,ultrasonic rolling technology,which is a surface treatment process that combines deep roll machining with ultrasonic vibration,is presented.The nano-hardened layer with gradient structure can be induced on the surface of Ti-6Al-4V alloy,which is an effective method,resulting in the enhancement of surface strength and further improvement of erosion resistance of the material.The present paper studies the effect of surface strengthening on the erosion wear properties of Ti-6A1-4V alloys.The main contents are as follows:(1)Improve the design of ultrasonic rolling equipment.The main innovation is the use of Bezier-curved ultrasonic horns,which optimized the vibration amplification performance of the horn and reduced the stress concentration on the components.(2)The microstructure of Ti-6A1-4V alloy after ultrasonic rolling process was observed by transmission electron microscopy and scanning electron microscopy.The grain-refined surface layer was formed with a thickness of 300 ?m.The grain size of the surface layer was less than 100 nm.Surface hardness distribution tests show that the ultrasonic rolling process increases the surface hardness of the material by approximately 30%.(3)The effect of rolling process on the erosion resistance of the material under different angles of attack was studied by comparative tests and finite element simulations.The erosion model of Ti-6Al-4V alloy was analyzed by observing the morphology of the material.After ultrasonic rolling treatment,the erosion resistance of the material was found to be increased twofold and in some cases threefold.It was also established that the impact of rolling treatment was greater under low impact angle.