Research Of Power Ultrasonic Double Vibration Heads Influence Toa356Aluminumalloy Semi-solid Microstructure

Since Semi-solid forming technology put forward, with its advantages of energysaving, near net forming caused by many scholars at home and abroad to study, thinkthat this technology has great development potential. But because the cost of preparingSlurry process is high, the production process is not stable, limiting its development ofRheoforming. Use power ultrasonic treatment technology preparing for semi-solidslurry can greatly reduce the cost, improve the production efficiency, can get grain small,uniform and spheroidization semi-solid slurry for rheoforming. At present, themechanism of power ultrasonic fine grain is not fully understood, application in thefield of semi-solid is less, have yet to research and development.This project is on the basis of research group former research, under the obliquerunner load power ultrasonic two vibration heads processing flowing the A356aluminum alloy melt, prepare excellent semi-solid slurry used for rheological dieforging. According to this train of thought, design a set of interlace power ultrasonicdouble vibration heads experimental treatment device, under the oblique runner bottomwelding two vibration heads, vibration head are respectively connected with1500W and1000W power generation system. Runner inclination angle can be adjusted. At the sametime also participate in design of subtend type experiment device. Study respectively thedifferent pouring temperature (600℃,620℃,640℃), different runner inclination angle(35°,40°,45°) as well as vibration head with different position relationship effect onsemi-solid slurry microstructure. According to the experimental results found in therunner Angle of40°, the pouring temperature of620℃, interlace power ultrasonicdouble head vibration experiment device got the best effect, the average grain size isonly33.7μm, shape factor is0.78, and the microstructure uniform. At the later stages ofthe experiment, combined the preparing slurry and rheoforming. According toexperimental analysis discovered that power ultrasonic prepared semi solid slurry thannot be treated by ultrasonic got better mechanical properties, by microstructure offorming comparison, discovered slurry after treated by ultrasonic forging microstructurewas smaller, more spherical.The projet combined power ultrasonic and inclined plate cooling method. Powerultrasound thermal effect and mechanical effect can effectively increase the nucleationrate, The flowing melt has a large number of crystallization nucleation formed, by scoured and power ultrasonic acoustic streaming effect makes nucleation distributionuniform, to make crystal grain uniform small, spheroidization. This projet break theprevious preparation of semi-solid slurry capacity limit and reduce power ultrasonicattenuation effect, production technology and equipment is simple. There is a certainindustrial application prospect.