| Summary: | 碩士 === 遠東科技大學 === 機械研究所 === 95 === Tungsten particles strengthened Copper matrix composites fabricated by powder metallurgy method was studied in the present work. The mechanical properties, electrical properties, and the thermal stability at elevated temperatures of the composites understudied will be discussed thoroughly in this thesis.
In the present work, researches were focused on several points including:
1. How the microstructures, properties, and thermal stabilities of
the composites were affected by the content and the size of the
strengthening phase.
2. What and how the process parameters affect the properties of the
Cu/W interface and the composites.
3. What and how the process parameters affect the recrystallization
temperatures of the composites.
4. How the mechanical and electrical properties were affected by
ambient temperature and soaking time.
The experimental results reveal that both the mechanical properties and thermal stabilities of the copper matrix were improved dramaticaly by the addition of tungsten particles. Owing to the impediment effect of the tungsten particles on the grain coarsening, the Cu-W composites attain improved thermal stability at elevated temperature. On the other hand, since copper and tungsten metal both possess very high electrical conductivity and are indissoluble in each other, the Cu-W composites should also possess excellent electrical conductivity. This is indeed the case. Actually, some Cu-W composites possess electrical conductivity higher than 90%IACS in the present work.
General speaking, the Cu-W composites in the present work possess excellent mechanical properties, electrical properties, and thermal stability at elevated temperature, and fit all the demands of high performance electrical contacts.
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