1976 Volume 45 Issue 4 Pages 289-294
This paper presents some experimental data concerning the relation between the shearing strength and roughness of base metal (mild steel) surface brazed with BAg 8. The specimens used in this experiment were made according to the configuration ofJIS Z3194, the same shape as designed by F.M. Miller and R.L. Peaslee.
To make the various roughness on the base metal, each specimen was identically finished by means of abrasive paper (60, 120, 240, 400 and 600 mesh) polishing and milling cutting or WA60 and WA80 wheel grinding. The brazing operations of these specimens were conducted using a 35Kw resistance furnace operated in hydrogen atmosphere, and joint clearance of each specimen was adjusted on the cementing fixture. To obtain the tensile-shearing strength value of these specimens, 50 tons tensile testing machine was used in this experiment. Tensile-shearing test of these specimens gave the results as follows:
(1) As regards the relation between the shearing strength of brazed joint and roughness of base metal surface, it was clear that shearing strength of brazed specimens having a small roughness value was greater than that of one having a large roughness value.
(2) The maximum shearing strength of brazed specimen was observed at the about 0.3 mm joint clearance.
(3) It was cleared that shearing strength of specimen having a long brazed joint length was lower than that of one having a short brazed joint length.
(4) Most of specimens failured at the filler metal zone, and a few of them failured at the interface of joint, but no specimen ruptured in the base metal.