Papers by Keyword: Diamond Tool

Abstract: An investigation is reported of the relationships of the temperatures and grinding parameter for grinding of ceramics with a brazed diamond grinding tool. During the experiments, the temperature distributions along the workpiece surface were measured using a foil thermocouples and the energy partition to the workpiece estimated using a temperature matching method. The results show that the grinding temperature increased with the increasing of worktable feed rate or tool velocity and depth of grinding. The measured temperature responses were found to be in good relation with the analytical results of a moving heat source with a rectangular distribution at the grinding zone.The energy partition ε is about 23%.

Abstract: Micro-machining of hard dies and molds for optical parts or precision instruments is required to extend die and mold life. This paper investigates the effect of cutting fluid on diamond tool life under micro V-groove turning of cobalt-free tungsten carbide. Zinc dialkyldithiophosphate fluid (ZnDTP) displayed excellent diamond tool wear resistance in previous experiments. The performance of this cutting fluid is compared to newly developed vegetable oil based cutting fluid with dispersed MoS₂ nanotubes. This paper investigates nanopolycrystalline diamond (NPD) tool life with a rake angle of 0° and-30° under continuous micro V-groove turning (i.e. face turning), of cobalt-free tungsten carbide using the developed cutting fluids. Superior diamond tool edge wear resistance is observed when using the dispersed MoS₂ nanotubes in vegetable oil and using a NPD tool with a-30° rake angle.

Abstract: Large wear of diamond tools for ultra-precision cutting of soft metals deteriorates quality of machined surface, and the worn tools have to be replaced with new tools when the tool wear reaches limited wear land width of cutting edge generating finished surface. However, it is difficult to predict the tool life since all cutting tools have individual tool life. Therefore, the purpose of this study is to estimate wear land width of cutting edge of a single crystal diamond tool having large nose radius by using static cutting forces during machining. As a result of the cutting tests and measurements, it was found that the ratio of thrust force to principal force had good relation with the ratio of flank wear land area to cutting cross section area. Furthermore, according to some detailed observation of flank wear, width of flank wear land was greatly related to uncut chip thickness obtained under different cutting conditions and it was found that width of flank wear land could be estimated by measured static cutting forces and cutting conditions.

Abstract: This article presents results of a study of the surface topography of nickel composite electrochemical coatings (CEC), reinforced alumina nanoparticles, and the test results of the diamond tool. Used as a reinforcing phase alumina nanopowder was obtained by electrical explosion of aluminum wire in oxygenated atmosphere and had an average particle size of 60-70 nm. Experiments showed that the inclusion of alumina nanoparticles in a nickel matrix modifies its structure and increases the strength properties, so the wear resistance of diamond-plating increased by 3 times.

Abstract: The study of the mechanical ruling process of aluminum grating needs a new test device. And a program controlled test device for mechanical ruling was analyzed, designed, manufactured and tested in this paper. The developed mechanical ruling techniques of this device to fabricate micropatterns are introduced with the characteristics of multiple degrees of freedom, openness, visualization, and operability. After some primary tests, assessment of microgrooves was performed with mini video microscopy, which confirmed the validity of the new device for mechanical ruling process investigation.

Abstract: Ultra-precision diamond cutting of ferrous metals has not been successful in application due to significant tool wear. In this work, numerical simulations and experimental investigations are presented in order to study the interface diffusion between diamond tool and workpiece materials. A diffusion model with respect to carbon atoms from diamond tool penetrating into chips and machined surface was established. The numerical simulation results of the diffusion process reveal that the distribution laws of carbon atoms concentration have a close relationship with diffusion distance, diffusion time and the original carbon concentration of the work material. In addition, diamond face cutting tests of die steels with different carbon content are conducted at different depth of cuts and feed rates to verify the previous simulation results. The wear morphology of rake face and flank face of diamond tool were detected by scanning electron microscopy. Energy dispersive X-ray analysis was proposed to investigate the change in chemical composition of the chips and machined surface. The results of this work benefit for a better understanding on the diffusion wear mechanism in single crystal diamond cutting of ferrous metals.

Abstract: In this study, we investigated ultra-precision cutting technology used in the production of Al alloy polygon mirrors. We compared characteristics of three Al alloys (Al–Mg, Al–Cu, and Al–Si) when cut with a straight diamond tool. When cutting Al alloys, it is desirable to reduce geometric surface roughness and remove tear-out marks and scratch marks. We investigated the relationship between end cutting edge length, surface roughness, and cutting force of straight diamond tools. In addition, we compared surface roughness and cutting force produced by double facet tools with microfacets at the end cutting edge and on the rake-face side. It was found that both tools have similar cutting characteristics and that Al–Mg has the best optical quality, followed by Al–Cu and Al–Si.

Abstract: The effects on the mechanical properties for three auxiliary abrasive with different hardness were researched by changing the content of the auxiliary abrasives in the phenolic resin-based bond in this paper. The abrasive tool sample's bending strength and Rockwell hardness were tested. It shows that with the increase of TiO₂ content, the hardness and strength reduced firstly, but then increased; and when the content of TiO₂ was 5%, the Rockwell hardness decreased by 30% and the bending strength fell by 44.98%. As the CeO₂ content increases, the hardness of the abrasive tool changed little, while the bending strength decreased more, and when its content was 1%, the bending strength decreased by 25.63%. When the content of SiO₂ is 3%, he bending strength decreased by 32.82%; and when its content is 5%, the Rockwell hardness reduced by 24.97%, and then its hardness has a substantial increase.

Abstract: During ultra-precision cutting of brittle materials, the wear of diamond tool seriously affects the quality of machined surface. By molecular dynamics modeling of nanometric cutting, the generation of graphitization and its formation process at the cutting edge of tool are observed. By analyzing the process, the reason of the graphitization wear is mainly thermo-chemical reactions. By calculating the changes of coordination numbers of the tool atoms, graphitization conversion rate keeps increasing along the cutting process but gets stable after a certain length, which indicates the graphitization wear will occur in the same process.

Abstract: FeCuCo alloys are the new generation of metal matrix for diamonds in PM processed cutting tools. These alloys were created with the purpose of reducing the cobalt content in diamond tools. Nevertheless, little have been published, once this is a matter of industrial interest. In this work, samples of Fe (10-20) wt. %Cu and Fe (10-20) wt. %Cu 1%wt SiCp alloys were processed by cold pressing at 350 MPa, followed by sintering at 1150 C/30 min. under argon atmosphere. After sintering, a study of structural and microstructural analyses was conducted. Brinell hardness and wear tests were carried out in the metal matrix, as well as the wear resistance of the metal matrix composites. The composition Fe-20%wt Cu-1%wt SiCp was the best among the studied ones, because it presented the best results of hardness and wear resistance.