3results about How to "Avoid severe oxidation" patented technology

This invention discloses a high-elongation cast Al-Cu-Zn-Mg alloy with good resistance to hot cracking. The alloy composition, by mass percentage, includes: Cu 3.5–4.5%, Mg 0.4–1.5%, Mn 0.2–0.5%, Ti 0.10–0.2%, Zn 2.5–3.5%, with the balance being Al and unavoidable impurity elements. Addressing the limitations of existing Al-Cu casting alloys, such as wide solidification temperature range, poor fluidity, and hot cracking, this invention provides a high-Zn-content Al-Cu-Zn-Mg alloy with good resistance to hot cracking. This alloy has a low melting point, a narrowed solidification temperature range, and excellent resistance to hot cracking and mechanical properties. It can be used for various high-strength cast aluminum alloy structural parts, effectively avoiding casting defects such as hot cracking, shrinkage cavities, and porosity, and significantly improving the overall mechanical properties of the alloy.

The invention provides a stainless steel pipe welder capable of preventing weld joint oxidation, and relates to the technical field of welding equipment, the stainless steel pipe welder comprises a welding assembly, a cover body part, a trailing part and a gas supply assembly, the trailing part comprises a lower groove part, a refrigeration sheet and an upper groove part, the opening of the lower groove part faces a stainless steel pipe workpiece, and a first channel is formed between the lower groove part and the workpiece; the upper groove piece is fixedly connected to the side, away from the workpiece, of the lower groove piece, and a second channel is formed. The refrigeration sheet is clamped between the lower groove piece and the upper groove piece, the cold end faces the lower groove piece, and the hot end faces the upper groove piece; when protective gas in the cover body part flows to the trailing part, first protective gas and second protective gas are formed, and the first protective gas flows through the first channel, exchanges heat with the cold end of the refrigeration sheet and then is cooled, so that the dual functions of protection and cooling are realized; and the second protective gas flows through the second channel, exchanges heat with the hot end of the refrigeration sheet, and drives the outside air to perform forced heat dissipation on the hot end by utilizing the gas disturbance effect.

This invention belongs to the field of advanced metallic materials and powder metallurgy technology, specifically relating to a low-cost, multi-scale twinned synergistic deformation superplastic medium-heavy alloy and its preparation method. The preparation method includes melting the medium-heavy alloy using vacuum induction melting technology, then casting the molten medium-heavy alloy into an ingot and machining electrodes; preparing the electrodes into powder of a predetermined particle size; loading the powder into a casing, and after compaction, heating and degassing the casing until the required vacuum level is met, followed by sealing the casing; hot isostatic pressing of the sealed casing, and finally machining to remove the casing, yielding the superplastic medium-heavy alloy material. The superplastic medium-heavy alloy material prepared by this invention possesses multi-scale twins and an FCC matrix, with the FCC matrix accounting for more than 95% of the alloy, both ensuring good plasticity of the medium-heavy alloy material.