Constitutional Phases and Performances of Cu-Sn-Ti Alloys in the Brazing of Diamond

• Main Authors: Yu-chan Hsieh, 謝育展
• Other Authors: sun-tian Lin
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/53589739739771918835

博士 === 國立臺灣科技大學 === 機械工程系 === 96 === Cu-Sn-Ti alloys are ideal brazing filler suitable for bonding application of diamond because of its high wetting and bonding abilities. This study discussed the effects of various composition of Cu-Sn-Ti alloys on the wetting phenomena of graphite, its constitutions, and their interfaces at the temperature ranging from 850~1000℃. It was found that the additions of Titanium enhancing the wetting ability of Cu-Sn-Ti alloys; however, although the additions of Tin could lower the melting temperature of the Cu-Sn-Ti alloys, it deteriorated the interface of between graphite and Cu-Sn-Ti alloys caused to affect the chemical bonding of the interface. When the content of Cu-Sn-Ti alloys was at constant low Tin concentration (10at.%), the Titanium addition produced the growth of hard intermetallic compound (IMC) phases, CuSn3Ti5, Cu2SnTi3, and SnTi3; when the content of Cu-Sn-Ti alloys was at constant low Titanium concentration (10at.%), the Tin addition produced the growth of brittle intermetallic compound (IMC) phases, Sn5Ti6 and Sn3Ti2, in the soft matrix. The result was found that the crack was easily occurred at the boundary of graphite and alloys if the constitution had lots of hard intermetallic compound phase (IMC). To verify the experiment results, four kinds of most used brazing fillers were used to bond CVD diamonds for testing bending strength. The test results indicated that the bending strength of joining CVD diamonds by using Cu-10Sn-15Ti (wt.%) pre-alloys was higher than those by using two kinds of Ni-Cr based alloys, Ni-7Cr-3B-3Fe-0.5Si (wt.%) alloys and Ni-14Cr-10P (wt.%) alloys, but it had the similar value of the bending strength between CVD diamonds, which used Ag-34.25Cu-1In-1.75Ti (wt.%) alloys as brazing filler for CVD diamonds.