Papers by Author: Bo Jiang Ma

Abstract: The high performance diamond brazed saw was developed to cut efficiently AZ31 Magnesium Alloy. The Ti-coated diamond and the uncoated diamond were brazed with NiCr alloy by high-frequency induction under argon atmosphere at 1040°C within 20 seconds. Scanning electron microscopy (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD) were used to investigate the interfacial microstructures between brazed diamond and the filler alloy. The results show that Cr-carbides forms normally and compactly on the surface of Ti-coated diamond brazed, whereas Cr-carbide forms tangentially and loosely on the surface of uncoated diamond brazed. That is because Ti has changed the mechanism of Cr-carbides formed on the surface of diamond brazed. The test of cutting AZ31 magnesium alloy plate shows that the section cut by Ti-coated diamond saw is much smoother than that cut by uncoated diamond saw after a long time.

Abstract: The high-powered brazing diamond saw was developed to cut vehicle tyre efficiently. The Ti-coated diamond and the uncoated diamond were brazed with NiCr alloy by high-frequency induction under argon atmosphere at 1020°C within 10 seconds. The interfacial microstructures between brazed diamond and the filler alloy were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersion spectrometer (EDS). It is surprisedly found that Cr-carbides forms compactly and normally on the surface of Ti-coated diamond brazed, whereas Cr-carbide forms loosely and tangentially on the surface of uncoated diamond brazed. The abrade experiment results for the brazed diamonds show that the bond strength between the Cr-carbide and uncoated diamond brazed is lower than the normally formed Cr-carbide and the diamond. Furthermore, the cause that Ti changes the morphology of Cr-carbides on the surface of Ti-coated diamond brazed is discussed by the further tests that are specially designed.

Abstract: The research and manufacture of endless diamond wire saws have been reported in this paper. The matrix of saws was 65Mn steel wire whose diameter was o.8mm, and was welded as a ring by argon arc welding. The endless diamond wire saws were made by setting diamond abrasives on endless steel matrixes using nickel-plating method. The cutting experiments were carried out using the diamond wire saws on the homemade test equipment. The characteristics of the saws are narrow slot, high cutting speed, low noises and good surface quality. The surface cut could be finishing grinding or polishing directly, so the productivity could be improved greatly. Endless diamond wire saws can cut not only rock, but also valuable hard and brittle materials such as ceramic, boulder, and silicon etc.

Abstract: The Ti-coated diamond and the uncoated diamond were brazed with Ni-based filler alloy by high-frequency induction under argon atmosphere at 1050°C within 15 seconds. The interfacial microstructures between brazed diamond and the filler alloy were analyzed by scanning electron microscopy (SEM), energy dispersion spectrometer (EDS) and X-ray diffraction (XRD). It is surprisedly found that Cr-carbides forms normally and compactly on the surface of Ti-coated diamond brazed, whereas Cr-carbide forms tangentially and loosely on the surface of uncoated diamond brazed. The abrade experiment results for the brazed diamonds show that the bond strength between the normally formed Cr-carbide and the diamond is higher than that between Cr-carbide and uncoated diamond brazed. Furthermore, the cause that Ti changes the morphology of Cr-carbides on the surface of Ti-coated diamond brazed is discussed by the further tests specially designed.