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Vol.36, No.7, 1169 ~ 1176, 1998
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| Title |
| A Study on the Electron Beam Weldability of A5083, A6061, A7075 Al Alloys for the Transportation Applications |
| 김성욱 Sung Wook Kim , 김숙환 Sook Whan Kim , 이창희 Chang Hee Lee |
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| Abstract |
| This study was performed to evaluate basic characteristics of electron beam weldability for high strength Al alloys. The Al alloys used ere non-heat treatable A5083-O and heat treatable A6061-T6, and A7075-T6. The principal welding process parameters, such as accelerating voltage, beam current, welding speed and chamber pressure were investigated. The dimension and microstructure of welds were evaluated with OLM, and SEM (EDAX). In addition, weldability variation (cracking and porosity formation) due to process parameters was also evaluated, The EBW machine used for the welding development has a maximum operating voltage of 150kV with a beam current of 100mA, giving a maximum output power of 15kW. Welds had many discontinuities such as cracks, cold shut, root porosity, and spikes. The tendency to form weld discontinuities was strongly dependent upon the EB process parameters and chemistry. Although three Al alloys were welded under the same conditions, alloying elements had an important effect on the dimension of the weld and weldability. A6061-T6 shoed lower depth than the others, The variation of the weld depth was found to be sensitive to the vaporization tendency of the alloying elements. Si, which is the major element of A6061-T6, was more difficult to vaporize than other elements (such as Al, Mg and Zn). |
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| Key Words |
| Aluminum alloy, Electron beam welding, Aspect ratio, Beam active parameter, Softening, Porosity, Spiking, Crack |
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