Structure and Performance of Chemical Duplex Plating Ti Metal Layer on Diamond Surface by Hydrothermal Method

As a surface of diamond has a higher interfacial energy and worse binding force, the diamond shed from matrix easily. For solving this, the microstructures and properties of the metallic coating on diamond surface were studied. The different temperatures, such as 110, 120, and 130 °C for 6 h, were used for coating diamond in the high-pressure reactor respectively. The structure and performance of the metallic coating on diamond surface were tested by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and diamond compressive strength instrument. The results showed that a continuous and compact coating of Ni, W and Ti on the diamond surface is obtained by the hydrothermal coating technology (chemical duplex plating) at 120 °C. After heat treatment at 850 °C for 1 h, the better layer coatings form for protecting diamonds and reducing the trend of oxidize. Because the carbides of W and Ti present at the boundries between the coating and diamond surface, the combination of chemistry and metallurgy is gotten. The compress strength of diamonds after hydrothermal and heat treatment is higher than that of uncoated particles (those are 54.40% and 85.48%, respectively).

Preparation of Cu-Coated Diamond Particles and its Influence on the Performances of Diamond/Cu Composites

Cu-coated diamond particles in variable mass ratio of diamond and Cu are prepared by electroless plating process, then the coated particles are sintered by Spark Plasma Sintering (SPS) respectively. Diamond/Cu composites with high content of diamond(70vol%) are obtained eventually. The results indicate that not only coating diamond by copper electroless plating process could be used to obtain well-dispersed Diamond/Cu composites, but also effectively to improve the relative density of the sintered body, the relative density of the sintered body at 70vol% content of diamond is about 97.5%, as well as to obtain the composite with higher thermal conductivity. Thermal conductivity of the 70vol% Diamond-Cu composite reaches as high as 404 W/(m•K).

Slicing Brittle Material with Active Braze Coating Diamond Wire

The slicing technology with active braze coating diamond wire has been studied to lower the manufacturing cost and to increase the efficiency of wire sawing. The study shows that the grains have strong retention on the resin matrix as well as longer tool life.

Creation of Diamond/Molybdenum Composite Coating in Open Air

In order to improve wear resistance of atmospheric thermal plasma sprayed molybdenum (Mo) coating, diamond deposition on the atmospheric plasma sprayed molybdenum coating by the combustion flame chemical vapor deposition (CFCVD) has been operated. Although diamond particles could be deposited on the molybdenum coating, the coating was fractured and peeling off due to thermal influencesin our previous study. In this study, to diminish the thermal damage of the substrate during operation, a thermal insulator was equipped between substrate and water-cooled substrate holder. Consequently, diamond particles could be created on the Mo coating without fracture and peeling off. From these results, it was found that this process had a high potential in order to improve wear resistance of thermal sprayed coating.