超声振动辅助磨削对DD6单晶高温合金材料去除的影响OA

Objectives:To improve the grinding efficiency and quality of DD6 single crystal high-temperature alloy,the influence of ultrasonic vibration-assisted grinding on material removal is analyzed.Methods:Conventional grinding(CG)and ultrasonic vibration-assisted grinding(UVAG)are performed perpendicular to the casting axis of the single crystal superalloy material.The influence laws of amplitude and grinding parameters on indicators such as grinding force and surface roughness are analyzed.Additionally,the influence of UVAG on the material removal process is examined in combination with grinding temperatures,grinding forces,and surface morphologies.Results:The results show that normal and tangential forces of UVAG are smaller than the ordinary grinding forces under the same parameters.In most cases,UVAG can reduce the surface roughness of the workpiece to different degrees.UVAG can reduce the risk of grinding burns.In the ordinary grinding process,the abrasive particles are in continuous contact with the workpiece,and continuous grinding marks can be obviously seen on the surface of the workpiece.In the condition of ultrasonic vibration,the surface of the workpiece can be found with obvious periodic short grinding marks.When the grinding depth ap=0.5 mm,the workpiece feeding speed vw=100 mm/min,and the grinding speed vs=30 m/s,the normal force Fn and tangential force Ft under ultrasonic vibration assisted state are about 60%smaller than that of ordinary grinding.The roughness decreases the most when ap=0.5 mm,vw=150 mm/min,vs=30 m/s,and the maximum value is equal to 30%.When ap=1.0 mm,vw=100 mm/min,vs=30 m/s,the UVAG temperature is still lower than the maximum applicable temperature of DD6,while the CG temperature exceeds the maximum applicable temperature of DD6,indicating that the UVAG can improve the material removal efficiency of DD6.Conclusions:High-frequency vibration optimizes the material removal mechanism which reduces the abrasive contact ratio and grinding forces during material removal by promoting the periodic"contact-separation-contact-separation"intermittent cutting behavior between abrasive particles and workpiece.At the same time,ultrasonic vibration improves the cooling conditions and helps the coolant to penetrate,allowing the coolant to enter the grinding area more efficiently and carry heat away.The temperatures of ultrasonic grinding are lower than that of traditional grinding.Ultrasonic vibration infuses the grinding process with a pulsating impact,transitioning the interaction between the abrasive particles and the workpiece from a state of constant contact to a pattern of intermittent engagement.This shift diminishes friction and wear at the interface,as well as curtails the adherence of material to the workpiece surface.Ultrasonic vibration effectively reduces grinding forces and grinding temperatures through intermittent cutting mechanism,lowers the difficulty of material removal,and ultimately improves the processing efficiency and surface quality of DD6 single crystal superalloy.