The effects of a Ti coating on the performance of metal-bonded diamond composites containing rare earth

The present study was undertaken to examine the effects of a titanium coating on the surfaces of diamond crystals embedded in a metal matrix containing rare earth. Either coated or uncoated diamonds was incorporated into copper, tin, iron, nickel, and rare earth powders. The powders mixed with diamonds were then hot-pressed to form two kinds of specimens. The transverse rupture strength (TRS) of the two specimens was measured and compared. The specimens were also machined by surface grinding using an alumina wheel. The consumed power was monitored in the grinding process. SEM and EDS were used to analyze the fractured and ground surfaces of the specimens. It was found that the TRS of the specimen containing coated diamonds increased by 21% as compared with uncoated diamonds. The consumed grinding power for coated diamonds was found to be lower than uncoated diamonds. Although the weight loss of the specimen with coated diamonds was higher than that of uncoated diamonds at initial grinding stages, it became almost same for both specimens after a period of grinding.