Grinding Force And Surface Integrity Of Titanium Alloy In Rotary Ultrasonic Vibration Grinding

With the development of science and technology, people have a higher request for material performance and machining precision to parts, the titanium alloy material has been widely used in manufacturing industry, especially in aerospace industry because of its excellent properties. For the hole processing technology of titanium alloy materials, through consulting the relevant literature, we have learned the research progress of ultrasonic vibration machining technology and the surface integrity of materials at home and abroad. The mechanism of ultrasonic vibration grinding was studied from the aspect of kinematics, and the grinding force model was established. To carry out experiments of rotary ultrasonic vibration grinding of TC4 titanium alloy, the grinding force and the surface integrity of hole wall were studied, work accomplished and conclusions are as follows:(1) Establishing the movement equation of abrasive particle motion of rotary ultrasonic vibration grinding, drawing the trajectory curve of abrasive particle. From the perspective of kinematics, the material removal mode of workpiece is mainly based on ultrasonic impact, accompanying with a certain scratch and plough. The grinding force model is established, and the processing parameters which affect the grinding force are obtained, providing reference for the setting and selection of process parameters in the actual machining process.(2) Setting up the experimental platform of ultrasonic vibration machining, selecting the experimental tool, carrying out ultrasonic grinding, ultrasonic drilling and traditional drilling experiment, and obtaining the experimental cutting force data. By doing the S/N ratio analysis and ANOVA analysis for the grinding force data of ultrasonic grinding, we obtain the influence of the parameters on the grinding force. Doing analysis of drilling force data of the ultrasonic drilling and conventional drilling, we can find that, under the same operating conditions, the ultrasonic drilling force is lower than conventional drilling. Comparing the advantages and disadva-ntages between the ultrasonic grinding and the ultrasonic drilling, and summing up its application range.(3) Detecting the surface integrity of hole wall in ultrasonic grinding. Analyzing the surface roughness data of the hole wall of the experiment, exploring the influence of processing parameters on the surface roughness in ultrasonic grinding experiment. Obtaining the microscopic images of hole wall after ultrasonic grinding, and analyzing the reasons of the forming process. Doing XRD analysis to the machined hole wall surface, According to the XRD analysis data, we do an analysis of surface material composition, which provides the basis for the analysis of burn and micro hardness on material surface.(4) By detecting the hardness of hole wall surface of ultrasonic grinding, gaining the hole wall surface micro hardness data, drawing the curves of micro hardness with surface depth. The depth of hardening layer and the percentage of hardening of the two processing methods are obtained. Analyzing the cause of hardening of the surface of the hole wall.