Abstract A braze-penetration barrier is provided for a sintered and infiltrated matrix-type of electrode or contact, so that, in effect, two joints are provided, one joint being provided between the metallic braze-penetration barrier and the sintered and infiltrated body portion of the matrix-type contact or electrode, and the other or second joint being provided between the metallic braze-penetration barrier member and the supporting rod-like metallic stem-portion of the interrupting contact or electrode. The braze-penetration barrier member may be provided, for example, by pressing a preformed braze-penetration barrier member with the particles of the matrix system in the press, which is subsequently sintered and infiltrated with a lower-meltingtemperature infiltrant material, such as copper or silver, for example, which penetrates into the pores of the higher-meltingtemperature matrix material, such as tungsten or chromium, for example.
The method of claim 1, wherein the refractory pulverulent material is selected from the group consisting of tungsten, chromium, molybdenum and their alloys.
Claim 2
Independent Claim
145 words
The method of fabricating an impregnated refractory contact structure for a circuit-breaker, comprising the sequential steps of: a. preforming a metallic plate-like barrier member into a cup-shaped insert; b. placing said cup-shaped insert within a mold; c. placing a predetermined quantity of metallic powdered matrix refractory pulverulent material only within the mold against said cup-shaped barrier insert; d. cold-pressing the refractory pulverulent material with the cup-shaped insert to result in a ''''green'''' contact member; e. removing the ''''green'''' contact member from the mold and subsequently sintering the same to remove gas therefrom; f. infusing the sintered powdered body with a metallic infiltrant selected from the group consisting of copper, silver and their alloys; whereby the cup-shaped insert is firmly bonded to the matrix body of the contact; and, g. metal-joining a metallic supporting stem portion to said cup-shaped insert and thus to the contact body.
Claim 3
Dependent Claim
24 words
The combination according to claim 3, wherein the refractory material is selected from the group consisting of tungsten, molybdenum and chromium and their alloys.
Claim 4
Dependent Claim
21 words
The method of claim 4, wherein the cup-shaped insert is selected from the group consisting of mild steel and stainless steel.