BRAZING OF HEAT-RESISTANT METALS
A program of research to study two phenomena important in the brazing of high-temperature alloys is described. These phenomena are dissolution of base metal in the molten filler metal, and penetration of filler metal into the grain boundaries of the base metal, The experimental approach utilized pad tests in which a pellet of filler alloy was melted on the base metal during a vacuum furnace brazing cycle, with 15 minutes at temperature. The range of filler alloys included Fe-B eutectic, Fe-Si eutectic, Ni-B eutectic, Ni-Si eutectic, Pd- B eutectic, Fe-Ge eutectic, Ni-Ge eutectic, and Fe-C-B alloy. Base metals included Armco iron, SAE 1045, high-carbon steel, 304 Stainless steel, 410 stainless steel, 15PH-7Mo stainless steel, nickel, and 80% Ni-20% Fe alloy. Only the FeB filler alloy showed a great tendency to grain boundary penetration: in plain carbon steels to an increasing extent with increasing carbon content, and in stainless steels if chromium were present. The role of secondary diffusion processes in influencing grain boundary penetration was shown. In general, Ni-B will penetrate Brain boundaries of the base metal if it picks up Fe by dissolution of base metal. Pd-B did not penetrate base-metal grain boundaries, but did dissolve extensive quantities of base metal at 2150 ction prod- F. Fe- Si formed extremely brittle alloy layers at the base metal-filler metal interface. (auth)
- Research Organization:
- Illinois Inst. of Tech., Chicago. Armour Research Foundation
- DOE Contract Number:
- DA-11-022-ORD-957
- NSA Number:
- NSA-14-010762
- OSTI ID:
- 4185992
- Report Number(s):
- AD-229022
- Resource Relation:
- Other Information: ARF Project No. B-039. Orig. Receipt Date: 31-DEC-60
- Country of Publication:
- United States
- Language:
- English
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