Arc pressure is the key influencing factor to forming of molten pool. Countering the characteristic of tungsten inert gas arc welding with micro gap for tantalum sheet, according to the fundament of arc physics, a dis...Arc pressure is the key influencing factor to forming of molten pool. Countering the characteristic of tungsten inert gas arc welding with micro gap for tantalum sheet, according to the fundament of arc physics, a distribution model of arc pressure and forming mechanism of molten pool with micro butt gap are proposed, and the influences of arc pressure on forming of molten pool are discussed. Experimental researches for the dynamic formation process of weld molten pool by using high-speed vidicon camera show that when butt gap is appropriate, that is from 0. 1 to 0. 15 mm, molten metals formed on two workpiece uplift and grow up first, then are fused and form uniform molten pool finally.展开更多
The effects of parallel and angular butt designs with different gap widths on the microstructure and mechanical properties of the resultant magnesium joints in gas tungsten arc welding were investigated. The experimen...The effects of parallel and angular butt designs with different gap widths on the microstructure and mechanical properties of the resultant magnesium joints in gas tungsten arc welding were investigated. The experimental results displayed that the tensile strength of the joint made with angular butt joint and 0.3 ram-wide gap reached 266 MPa, the joint fractured through the heat-affected zone or base metal during tensile testing, and the microstructure examination showed that no macropore appeared in the fusion zone. However, macropores in diameter of larger than 200 micron occurred for other joint designs, the tensile strength of the resultant joints decreased, and the joints fractured through the fusion zone during tensile testing. The fracture surfaces were examined by scanning electron microscopy and the microhardness distribution in the joints was measured by using a Vickers microhardness tester.展开更多
文摘Arc pressure is the key influencing factor to forming of molten pool. Countering the characteristic of tungsten inert gas arc welding with micro gap for tantalum sheet, according to the fundament of arc physics, a distribution model of arc pressure and forming mechanism of molten pool with micro butt gap are proposed, and the influences of arc pressure on forming of molten pool are discussed. Experimental researches for the dynamic formation process of weld molten pool by using high-speed vidicon camera show that when butt gap is appropriate, that is from 0. 1 to 0. 15 mm, molten metals formed on two workpiece uplift and grow up first, then are fused and form uniform molten pool finally.
基金supported by the State Key Lab of Advanced Welding and Joining,Harbin Institute of Technology (Project No.09009)
文摘The effects of parallel and angular butt designs with different gap widths on the microstructure and mechanical properties of the resultant magnesium joints in gas tungsten arc welding were investigated. The experimental results displayed that the tensile strength of the joint made with angular butt joint and 0.3 ram-wide gap reached 266 MPa, the joint fractured through the heat-affected zone or base metal during tensile testing, and the microstructure examination showed that no macropore appeared in the fusion zone. However, macropores in diameter of larger than 200 micron occurred for other joint designs, the tensile strength of the resultant joints decreased, and the joints fractured through the fusion zone during tensile testing. The fracture surfaces were examined by scanning electron microscopy and the microhardness distribution in the joints was measured by using a Vickers microhardness tester.
