69 results about "Weld microstructure" patented technology

The invention discloses a method for improving a weld microstructure of Al/Cu friction stir welding in a follow-up manner. The method comprises the following steps: (1) adjusting the lowest working pressure, and adjusting the lowest pressing amounts of microstructure modification mechanisms; (2) adjusting the positions of the microstructure modification mechanisms by virtue of an adjustment-control mechanism, wherein two rolling wheels in a microstructure modification mechanism (II) with double rolling wheels correspond to the whole thermo-mechanical affected zone at an Al/Cu side as well as a part of a weld heat-affected zone and a part of a weld nugget zone; (3) starting up temperature control systems of the microstructure modification mechanisms, setting a modification temperature, setting a temperature T1 of the rolling wheels of a microstructure modification mechanism (I) to 290-315 DEG C, presetting a temperature T2 of the rolling wheels at an Al side of the microstructure modification mechanism (II) to 275-290 DEG C, setting a temperature T3 of the rolling wheels at a Cu side to 480-510 DEG C, heating the three rolling wheels to the modification temperature and then stopping heating; and (4) starting up a friction stir welding machine to start welding, enabling the microstructure modification mechanisms to start to work, and ensuring that the modification temperature set in the step (3) is achieved and stabilized until weld modification is ended during working by virtue of the temperature control systems of the microstructure modification mechanisms, wherein modification for the microstructure of the heat-affected zone can be realized after the end of the welding.

The invention provides a 3D additive-manufacturing bilateral laser welding method for a T-shaped structure, relates to a double-laser-beam welding method, and aims to solve the problems that under the conditions of high welding speed and long weld beads, in a bilateral laser welding process of a T-shaped structure, the circumstance that welding wires are continuously and stably fed into a molten pool at constant speed and even, coherent and non-defective bilateral weld joints are obtained by one-time welding is difficult to ensure, and alloy of weld microstructures is difficult to regulate and control specifically and flexibly. The method comprises the following steps: 1, chemically cleaning the surface of a stringer; 2, designing of a sedimentary layer: designing the sedimentary layer in a region to be welded on the surface of the stringer, wherein the cross section of the sedimentary layer is square or rectangular; 3, vertically placing a laser cladding head at a position right above the region to be welded on the surface of the stringer, carrying out laser 3D additive-manufacturing on regions to be welded on two sides of the stringer to obtain the sedimentary layer in a mode of coaxially feeding laser beams and alloy powder; and 4, carrying out bilateral laser welding on the stringer and an envelope to obtain bilateral symmetric weld joints. The 3D additive-manufacturing bilateral laser welding method for the T-shaped structure is used for double-laser welding of the T-shaped structure.