Study On Rotary Ultrasonic Machining For Brittle Materials

In traditional ultrasonic vibration machining, abrasive driven by tools hit the workpiece's surface continuously to achieve the purpose of removing material. There have been great breakthroughs in brittle materials processing, but problems such as tools abrasion, low processing precision and efficiency still remain. Compared traditional ultrasonic grinding, rotary ultrasonic grinding processing, which makes use of electroplated or sintered diamond tools, overcomes these shortcomings, a smaller cutting force, much lower cutting heat at the sametime. So it is suitable for various brittle materials processing and becomes the focus of brittle materials processing applications and research. At present, researches of this type of equipment have been done by some developed countries, but relatively rare in our country. In addition, there is still more room for improvment in the field of processing technology and improveing equipment's quality.Common rotary ultrasonic grinding equipment is mostly using brush-contact power supply, there are two main disadvantages: big changes on the machine spindle; brush is easy to wear and seriously lost steps when high-speed rotating. The ultrasonic vibration system which connects the machine and tools, is usually bulky and has poor universal, so that it can only be applied on a specific machine. To solve these problems, this research introduces work as follows:1) Use electro-magnetic conversion to realize non-contact power supply.2) Programmable digital frequency synthesis ultrasonic power was researched and developed.3) A tool holder with a standard spindle interface integrated transducer and the horn of the ultrasonic vibration system was studied and developed.4) The whole system was established at the base of high-speed machine. Typical brittle material processing experiments were done to prove that the equipments can transform an ordinary high-speed machine into rotary ultrasonic grinding equipment.