Abstract
Butt welding-brazing of titanium alloy Ti-2Al-Mn to aluminum 1060 plates was investigated by pulsed gas metal arc welding using an AlSi5 filler wire. Microstructure characteristics of Ti/Al dissimilar joint were observed by scanning electron microscope. Chemical composition and phase constituent of Ti-Al transition region were investigated using energy-dispersive spectrometer and X-ray diffraction. Micro-hardness distribution of the weld zone was tested by micro-sclerometer. The experiment results indicated that joint free of pores and cracks could be obtained by controlling the welding process. The weld metal was composed of α-Al dendrites and α-Al+Si eutectic phase. The intermetallic compound TiAl₃ appeared in the weld metal. A multilayered Ti-Al transition region containing TiAl₃, Ti₇Al₅Si₁₂ and α-Ti had formed adjacent to the Ti/Al interface. Micro-hardness of the transition region was about 280HV_0.05. The heat-affected zone of Ti-2Al-Mn alloy was mainly composed of acicular α′ and lath α′ martensite phases. Micro-hardness of the heat-affected zone was 220–270HV_0.05.

Key words
Ti-2Al-Mn alloy, Al 1060, pulsed gas metal arc welding, microstructure, micro-hardness

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