Effects of Surface Preparations of Base Metal on the Butt Joint Strength of Mild Steel Brazed with BAg-8 (Report 8)
Capillary Penetration of Filler Metal
1973 Volume 42 Issue 6 Pages 526-538
Details
1973 Volume 42 Issue 6 Pages 526-538
The purpose of this study is to make clear the effect of surface roughness of base metal on the spread area of both Pb-Sn alloy and BAg-8 filler metal in the capillary of mild steel plates. And also, this investigation was conducted regard to the spread area of water in the parallel capillary of silicate glass plates, in order to obtain some experimental data of relation between roughness effect of glass plates surface and the spread area of water in the glass plates capillary. These experiments were carried out as follows:
These mild steel specimens with the capillary of 10×Hmm sectional area were dipped in the molten solder at 250°C or BAB-8 filler metal at 900°C' The spread area of these specimens were measured by planimeter.
In addition, the silicate glass specimens with the cpillary of 10×Hmm sectional area were dipped in the water at 20°C, and the rising phenomena of water in the capillary of lgass plates were taken in the motordrived photograph pictured by one frame per minute rate.
The results of these experiments were showed as follows:
1) The spread area of Pb-Sn alloy in the capillary of mild steeel plates with coarse surface was greater than that of one with smooth surface.
This tendency was observed in the case of BAg-8 filler metal in the capillary of mild steel plates. However, these phenomena of filler metal did not showed in the case of large value of H.
2) As well-known capillary theory, the spread area of BAg-8 filler metal in the mild steel plates capillary with small value of H was greater than that of one with large value of H. The same result was obtained in the experiment of water-silicate galss plates capillary. But, the reverse tendency was observed in the result of Pb-Sn alloy mild steel plates capillary experiment.
3) Rising speed of water in the cpillary of silicate glass plates with the smooth sufrace, was higher than that of one with coarse surface.
