| 摘要 |
<p>A sintered brazing alloy comprising a sintered felted mass of randomly dispersed Ni fibres and a lower melting point Ag base alloy is made by impregnating the felted Ni with the Ag base alloy in a non oxidizing atmosphere and mechanically working the product. The felted Ni has a porosity of 80% - 90% by volume and is made from wire 20 microns diameter 1/8 " - 1/2 " length, preferably crimped. The wires are slurried with e.g. water, felted by suction through a screen and sintered at 2200 DEG F. - 2300 DEG F. in a non-oxidizing atmosphere. The Ag base alloy may consist of (1) 84.6% Ag, 2.2% Pd, 7.5% Cu, 5.5% In and 0.2% Li; or (2) 92.5% Ag, 7.3% Cu and 0.2% Li. The impregnation may be effected in a graphite or alumina mould at a temperature of 1700 DEG F. - 1800 DEG F. for alloy (1) or 1760 DEG F. - 1860 DEG F. for alloy (2) in nitrogen or a vacuum. The brazing alloy is then rolled to strip or sheet form.</p> |
