Microstructure of a Mono-layered Diamond Tool Processed Using a Cu-Al-Ti Brazing Alloy

• Main Author: 陳維燕
• Other Authors: 陳適範
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/01972688560115332103

碩士 === 國立臺北科技大學 === 材料及資源工程系碩士班 === 90 === Abstract Diamond grits were brazed onto a steel substrate using a Cu-Al-Ti brazing alloy. The components of brazing alloy was Cu3Al pre-alloy powder, added 15wt%、20wt% and 25wt% Titanium powder, brazed temperature ranging from 950℃ to 1050℃ with isothermal holds 15 minutes in a vacuum(10-4~10-5 torr) environment. There were Al-Ti intermetallic compound(Ti3Al) and Cu-Al-Ti ternary alloy compound. The phase of Ti3Al was determined by XRD, the Cu-Al-Ti ternary alloy compound was Cu2-Al-Ti determined by EPMA. The reaction of Ti with diamond yielded a continuous TiC layer on the surface of the diamond grits. The thickness of the TiC layer was determined by TEM and the range was from 200 to 300 nm. The TiC film was grown on diamond (110) substrate, and the TiC grains were similarly developed in a tilt growth along the 〔110〕 axis on the diamond (110) plane. The Ti has affinity with diamond(C), the distribution of Ti tended to segregate to the interface between the diamond grit and the brazing alloy when the brazing was carried out with added 15wt%Ti at 1000℃. When the temperature and the additive quantity was increased, the distribution of Ti would tend to the base of brazing alloy. The hardness of brazing alloy increased when the temperature and the additive increased. The bending strength increased when the temperature from 950℃ to 1050℃ and the Ti content from 15wt% to 20 wt%. When the Ti content was 25wt% the size of educt was too big that reduce the toughness of the brazing alloy. Keywords：brazing, Cu-Al-Ti, intermetallic compound