Microstructures and mechanical properties in laser beam welds of titanium matrix composites. (February 2014)

• Record Type: Journal Article
• Authors: Mao, J. W.; Lu, W. J.; Wang, L. Q.; Qin, J. N.; Zhang, D.
• Is Part Of: Science and technology of welding & joining. Volume 19:Number 2(2014:Feb.)
• Page Start: 142
• Page End: 149
• Publication Date: 2014-02
• Subjects: Titanium matrix composites, -- Laser beam welding, -- Mechanical properties, -- Microstructure; Welding -- Periodicals; Joints (Engineering) -- Periodicals; Surfaces (Technology) -- Periodicals; 671.52
• DOI: 10.1179/1362171813Y.0000000176
• Languages: English
• ISSNs: 1743-2936

Abstract

Abstract : Laser beam welding (LBW) was used to 2 mm thick titanium matrix composites (TMCs) sheets and microstructure, hardness and tensile properties of butt joints were studied. Welded joints without defects were obtained indicating that LBW is a suitable processing method for TMCs. The results reveal that the fusion zone completely consists of α ′ martensite causing an increase of more 27% in hardness compared with that of base metal. The heat affected zone consists of a mixture of α ′ martensite and primary α phases. Large gradients of microstructures and hardness are found over the narrow heat affected zone dependent on the β -transus temperature during weld cooling. TiBw with smaller sizes redistribute at grain boundaries in the weld. The joints show excellent strength and they can reach the full strength compared with the base metal with sound welding parameters, which is ascribed to the presence of α ′ martensite and refinement of TiBw in the weld.