Papers by Keyword: PCD Tool

Abstract: The drilling of microholes in hard and brittle materials by ultrasonic grinding was carried out using polycrystalline diamond (PCD) micropins fabricated by electrical discharge machining. They can be employed as micro-grinding tools because the convex parts of discharge craters formed on the tool surface can serve as cutting edges of abrasive grains in grinding wheels. In the drilling of crown glass, the increase in the grinding force and the generation of cracks and chippings at hole edges were suppressed owing to the high wear resistance of PCD. Under suitable conditions, drilling was also successfully performed in silicon, which is apt to exhibit cracks and chippings at hole edges.

Abstract: High-speed milling tests were performed on vol. (5%-8%) TiC_p/TC4 composite in the speed range of 50-250 m/min using PCD tools to nvestigate the cutting temperature and the cutting forces. The results showed that radial depth of cut and cutting speed were the two significant influences that affected the cutting forces based on the Taguchi prediction. Increasing radial depth of cut and feed rate will increase the cutting force while increasing cutting speed will decrease the cutting force. Cutting force increased less than 5% when the reinforcement volume fraction in the composites increased from 0% to 8%. Radial depth of cut was the only significant influence factor on the cutting temperature. Cutting temperature increased with the increasing radial depth of cut, feed rate or cutting speed. The cutting temperature for the titanium composites was 40-90 °C higher than that for the TC4 matrix. However, the cutting temperature decreased by 4% when the reinforcement's volume fraction increased from 5% to 8%.

Abstract: By 3D finite element simulation for temperature field and tool wear of SiCp/Al metal matrix composites under the condition of high speed milling, we draw a conclusion that the most significant influence on cutting temperature is cutting speed, less is feed rates, the minimum is cutting depth, which is exactly the same as the influence law of ordinary metal cutting. In the course of high-speed milling SiCp/Al by PCD tools, the higher the cutting speed is, the bigger wearing depth of tools is. When v=300m/min, ap=0.5 mm, f=0.3 mm/r, the transient temperature in the milling would reach to 619°C. Such a high temperature can cause graphitizing wear of the PCD tools. Because of the effectiveness of the simulation’s conclusion, it is vital significance to the reasonable options of cutting parameters and the prolongation of tool life.

Abstract: Titanium alloy is widely applied in various fields, but it’s a sort of difficult-to-cut material. In this paper, DEFORM-3D is used to carry on a simulation of PCD tool milling Ti6A14V. Variation curves of cutting temperature and cutting force are obtained by changing cutting speed, feed per tooth and axial cutting depth. Further, the effect of cutting parameters on cutting temperature and cutting force is revealed. The research shows that cutting temperature and cutting force increase with cutting parameters. In addition, single factor experiments are conducted to verify that the results of the experiments are in consistent with those of the simulation, and that the simulation model is correct. The results will provide new methods for studies of cutting temperature and cutting force of PCD tool milling Ti6A14V.

Abstract: Titanium matrix composites (TMCs) possess many outstanding properties and have increasing and potential application in aerospace, automobile and other industries. However, TMCs are typical difficult-to-machining material due to the rapid tool wear rate and excessive machining induced defects. In this paper, tool wear, cutting forces, cutting temperature and surface roughness were investigated when milling TMCs with Polycrystalline Diamond (PCD) and carbide tools. The results showed that the values of surface roughness obtained by carbide tools were higher than that of PCD tools under the same cutting conditions. The value of cutting temperature for PCD tool was about 75% of the carbide tools, and the main cutting force value of PCD tool was about 85% of the carbide tool. Abrasive and adhesive wear were the main wear mechanisms of PCD and carbide tools. In all, PCD tools had a better cutting performance than carbide tools during finishing milling titanium matrix composites.

Abstract: High-speed turning tests were performed on vol.10%(TiC_p+TiB_w)/TC4 composite (TMC) in the speed range of 60-120m/min using PCD and carbide tools to investigate the tool life, tool wear, cutting temperatures and cutting forces. The results showed that the carbide tool was not suit for the machining of TMC. Tool life of PCD was confined to 12 min for all the cutting conditions. Flank wear increased obviously with the increasing cutting speed especially when the cutting speed surpassed 80m/min. PCD tool mainly took place chipping, peeling, abrasive wear and adhesive wear at the rake face and flank. The cutting temperatures of carbide were about 1.5-2.0 times higher than that of the PCD. Under the same cutting condition, cutting temperature of TMC was nearly 100°C higher than that of the TC4 matrix. The cutting forces were confined to 130N and 150N for the PCD and carbide tool respectively. For the carbide the cutting forces slightly decreased when the cutting speed increased from 60m/min to 120m/min. When using the worn tool, the cutting forces significantly decreased with the increasing cutting speed especially for the peripheral force component.

Abstract: Titanium alloy is a kind of materials difficult to be machined. In this paper, the author performed the wear experiment of polycrystalline diamond (PCD) tool in precision cutting of titanium alloy material Ti-6A1-4V, and carried out test for morphology and composition of the wear area of tool using scanning electron microscopy and energy dispersive analyzer. The results showed that the hard particles wear and adhesive wear were main reason for cutting tool wear, and main wear form is flank wear.

Abstract: The demand for surface quality and dimensional accuracy of ferrous metallic components has increased markedly at present. Whereas, it is clear known that diamond tool could not be used for cutting operation of ferrous metals ascribed to excessive tool wear. In this paper, a series of experimental investigations for various stainless steels with ultrasonic vibration assisted turning were proposed. The micro-morphology of rake and flank face of diamond was detected by scanning electron microscopy, in order to discuss the influence law of material composition on tool wear. In addition, the effect of cutting parameters such as depth of cut, feed rate and amplitude on tool wear and surface quality were deeply studied with ultrasonic vibration cutting. The results revealed that this technological measure has enhanced tool life, decreased cutting force and improved surface quality to a large extent.

Abstract: New exotic materials such as titanium alloys and carbon fiber reinforced plastics require strong hard cutters made of cubic boron nitride or polycrystalline diamond. However, the traditional mechanical diamond grinding process is slow and causes damage to the workpiece. This chapter examines the design requirements of an electrical discharge machining system that can be used to machine polycrystalline diamond tipped carbide drills. A preliminary theoretical model is described but the system complexity requires a gain scheduling approach to the control system design.

Abstract: Polycrystalline Diamond (PCD) tools are widely used while machining wood-based composites because of its outstanding hardness, thermal conductivity and abrasive resistance. However, the above mentioned beneficial properties such as super hardness also cause problems in manufacturing PCD tools using traditional process methods. The main problem now in manufacturing PCD tools is the low efficiency and difficulties while manufacturing PCD tools with complex curved surface. To manufacture PCD tools with complex curved surface more efficiently, in this paper, the mechanical structure, hardware circuit and software system of five-axis EDG CNC system are introduced. To satisfy the unique requirements of EDG, a proper mechanical structure of 5 CNC controlled axis and 2 manual axis are given, as well as the design of hardware circuit of EDG based on PCI Bus. The software system which is designed based on RT-Linux is divided into four modules: real-time cyclical tasks module, real-time gusty tasks module, non real-time tasks module and EDG process database. , This paper gives out the solutions of the specific functions of this special CNC system, including automatic measurement, automatic programming, automatic electrode wear compensation, and detection and control of spark gap. The detailed structure and organization of the software system is also provided. At last, through actual cutting experiments of woodworking PCD tools, the correctness and practicality of this system is verified.