Accession Number : AD0488047

Title :   ELECTRON-BEAM WELDING OF BERYLLIUM.

Descriptive Note : Final technical rept. 1 May 65-31 Mar 66,

Corporate Author : BATTELLE MEMORIAL INST COLUMBUS OH

Personal Author(s) : Hauser, D. ; Mishler, H. W. ; Monroe, R. E. ; Martin, D. C.

Report Date : JUL 1966

Pagination or Media Count : 144

Abstract : Electron-beam welding procedures were developed for 0.020-, 1/16-, 1/8-, and 1/4-inch thick beryllium sheet. For the three thicker sheets, weld undercutting and surface roughness were major obstacles in the development of satisfactory procedures. Welding procedures were developed that alleviated or entirely eliminated undercutting and surface roughness. Films observed on weld surfaces contained a large percentage of beryllium oxide. The thickness of these films increased with the oxide content of the base metal. Weld undercutting, surface roughness, and porosity increased with the beryllium oxide content of the base metal. The effects of restraint on weld cracking were evaluated by determining the preheat temperature necessary to prevent cracking when high and low restraint were imposed on butted sheets. Higher preheat temperatures were necessary when the restraint was increased. Weld distortion was measured in beryllium and compared to distortion produced in aluminum and stainless steel by electron-beam welding. Transverse shrinkage and longitudinal bowing were measured. Multiple-pass welds made with a low-power-density electron beam produced greater shrinkage that did single-pass welds made with a high-power-density electron beam. Measurements of longitudinal bowing indicated that the three metals behaved in a similar manner. Bend tests and tensile tests were performed with base-metal and welded specimens that were 1/16- and 1/8-inch thick. Bend transition temperatures from ductile to brittle behavior were about twice as large for transverse-bend specimens as for base-metal specimens. Greater bend ductility was exhibited by specimens having lower amounts of beryllium oxide.

Descriptors :   *BERYLLIUM), (*ELECTRON BEAM WELDING, SURFACE PROPERTIES, BERYLLIUM COMPOUNDS, OXIDES, FILMS, ALUMINUM, STAINLESS STEEL, MECHANICAL PROPERTIES, MICROSTRUCTURE.

Subject Categories : Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE