4results about How to "Grain refinement is obvious" patented technology

This invention discloses a laser-shock-assisted creep aging forming method for thin-walled components with complex curvature. The method includes: simulating and obtaining difficult-to-form regions; performing laser shock on the difficult-to-form regions of a large-size aluminum alloy thin-walled component sheet; wrapping and fixing a breathable felt around the impacted component; placing the component in a sealed space formed between a vacuum bag and the mold surface; evacuating the sealed space; and then sending the mold into an autoclave for creep aging. After completion, the component springs back, yielding the target surface. This method uses a laser to impact localized areas of a large-size aluminum alloy thin-walled component, introducing dislocations while achieving pre-forming. This provides a good surface foundation for subsequent high-precision creep aging forming of the component, and is suitable for forming parts with complex curvature.

The invention discloses a nickel-vanadium alloy target grain refinement method and an equal channel angular extrusion die, and belongs to the field of metal material machining severe plastic deformation. The method comprises the steps that a nickel-vanadium cast ingot is subjected to homogenizing annealing (1200 DEG C / 2 h, AC), then 8-pass extrusion is conducted through a BC path, and the total deformation is 165%. Each pass of extrusion is divided into three stages, the extrusion rates of the first four passes are the same, and the extrusion rates of the last four passes are relatively slow. The extrusion rate of each pass in the first four passes of extrusion is 10mm / s, 8mm / s and 6mm / s, and the extrusion rate of each pass in the last four passes of extrusion is 8mm / s, 6mm / s and 4mm / s. The equal channel angular extrusion die is composed of an L-shaped channel, the inner angle of the die is 120 degrees, and the outer angle of the die is 30 degrees. Then stress relief annealing (700 DEG C / 1 h, AC) is carried out; then large-deformation cold rolling is carried out, the deformation is 90%, and a sample is thinned to 3 mm; and then the plate is subjected to recrystallization annealing (550-850 DEG C / 1 h, AC). Compared with the prior art, the obtained structure is compact and has few defects, the structure is uniform, crystal grains are fine, and the strength is improved.

The invention discloses a preparation method of a zirconium alloy welding wire for obtaining a high-strength corrosion-resistant welding joint, which comprises the following steps of: 1, preparing a zirconium alloy cast ingot, forging to obtain a forging stock, and carrying out multi-pass hot rolling to obtain a wire blank; 2, coating the surface of the wire blank with a lubricant; and thirdly, the wire blank coated with the lubricant is subjected to multi-pass hot drawing and then sequentially straightened and polished, and the zirconium alloy welding wire is obtained. Multi-pass hot drawing is adopted, the forming temperature is high, the plastic deformation capacity is improved, the annealing frequency can be reduced, cracks are not likely to be generated in the drawing process, and therefore the production efficiency is greatly improved, in addition, a lubricating agent is used in cooperation in the drawing process, the flow shear stress is reduced, the surface smoothness and precision of the zirconium alloy welding wire are improved, and the production cost is reduced. The prepared welding wire has the advantages of being compact in microstructure, fine in grain, smooth and tidy in surface and high in size precision, and the corrosion resistance and the mechanical property of a zirconium alloy welding joint are remarkably improved through the prepared welding wire.

This invention belongs to the field of aluminum-copper alloy casting technology, and particularly relates to an in-situ particle-reinforced aluminum-copper alloy and its preparation method. The aluminum-copper alloy comprises the following components by weight percentage: 6.0% < Cu < 7.5%, 0.3% < Mn < 0.5%, 0.2% < Cd < 0.5%, 0.1% < Zr < 0.3%, 0.05% < Ti < 0.5%, 0 < V < 0.2%, 0.005 < B < 0.5%, 0 < Ce < 0.5%, with the balance being Al. This invention enhances the strength and plasticity of the alloy by adding a powder mixture of K2TiF6, KBF4, and CeO2 to form dispersed in-situ TiB2 particles; simultaneously, the addition of Ce disperses the TiB2 particles and other precipitated phases in the matrix, resulting in significant grain refinement and narrowing of the dendrite spacing.