| 摘要 |
<p>The thermal conductivity of a sintered copper/refractory metal composite having a maximum porosity of about 1 % is greatly improved when the composite contains phosphor and sintering aid in a specified weight ratio, 'phosphor/sintering aid ratio'. The copper/refractory matrix composite herein comprises, by weight, from about 5 % to about 30 % copper, from about 0.2 % to about 0.6 % sintering aid, from about 0.08 % to about 0.3 % phosphor, the remaining metal is refractory metal. The phosphor to sintering aid ratio ranges from about 0.25 to about 0.55. In one embodiment of the invention the sintering aid contains cobalt and the refractory metal is tungsten. The process for making copper/refractory metal composites having improved thermal conductivity, comprises selecting powdered metals comprising copper, sintering aid, phosphor and refractory metal; mixing the powdered metals to form a mixture of powdered metals; forming a green compact with the mixture of powdered metals; and sintering the green compact, containing chemically-bound oxygen in an amount sufficient to improve sintering, in a reducing atmosphere to form a copper/refractory metal composite that has a density of at least 99 % of theoretical.</p> |
