53results about How to "No undercut" patented technology

The invention relates to a vanadium intermediate layer-added titanium alloy-stainless steel dissimilar metal laser welding method, and belongs to the technical field of material welding (connecting). The formation of an omega brittle phase in a titanium alloy-vanadium welding seam and a sigma brittle phase in a vanadium-stainless steel welding seam is controlled and the brittleness of a joint is reduced by precisely controlling welding process parameters by adopting laser as a welding heat source and taking vanadium as an intermediate layer. A high-quality and high-efficiency welding joint which contains a titanium alloy-vanadium welding seam and an un-molten vanadium layer-stainless steel welding seam and is made of dissimilar metals is obtained by adopting two-time welding. The vanadium intermediate layer-added titanium alloy-stainless steel dissimilar metal laser welding method comprises the following steps: performing plate grouping and clamping, performing titanium alloy-intermediate layer-stainless steel contact surface pre-tightening force regulating, and welding a titanium alloy-vanadium contact surface and a vanadium-stainless steel contact surface respectively, so that the connecting of titanium alloy-stainless steel dissimilar metals is realized. The vanadium intermediate layer-added titanium alloy-stainless steel dissimilar metal laser welding method has the advantages that a laser welding process is stable; a welding seam is attractive; the welding defects, such as cracks, air holes, undercut edges, incomplete welding and incomplete fusing, are avoided; and the welding process performance is good.

The invention discloses a stainless steel-titanium alloy different metal laser welding method. The method takes laser as a welding heat source and niobium is added between stainless steel and a titanium alloy as an intermediate layer. By accurately controlling welding process parameters, a compound connector (titanium-niobium melting connection and niobium-iron liquid-phase dispersion connection) with two connection states is formed under a one-step heating condition, so that high-quality and high-efficiency welding of a stainless steel-titanium alloy different metal material is realized. By controlling the thickness of the intermediate layer and a welding speed of laser welding, metal niobium, which is not melted and has a certain thickness, exists between a titanium-niobium melting-welding welding seam and a niobium-iron liquid-phase dispersion-welding welding seam, and titanium and iron elements are prevented from mutual dispersion to form a crispy iron-titanium intermetallic compound. Finally, a formed welding seam has a beautiful shape, welding technological properties are good and the tensile strength is relatively strong.

The invention discloses a welding material composition for flux adhesive fiberglass backing (FAB). The welding material composition comprises a welding wire, a surface welding flux and filler powder.The welding wire comprises 0.08%-0.17% of C, 0.01%-0.04% of Si, 1.0%-2.5% of Mn, 0.1%-0.5% of Cr+Ni, 0.010%-0.025% of S, 0.010%-0.025% of P, and the balance Fe powder. The surface welding flux comprises 10%-20% of SiO2, 15%-35% of MgO, 5%-15% of TiO2, 7%-20% of Al2O3, 5%-20% of CaO, 0.01%-0.04% of S, 0.01%-0.04% of P, 0.01%-0.1% of H2O, 0.1%-0.2% of impurities and the balance Fe powder. The fillerpowder comprises 0.004%-0.01% of C, 0.01%-0.4% of Si, 1.0%-2.5% of Mn, 2.0%-5.0% of Ni, 0.2%-1.0% of Mo, 0.02%-0.04% of S, 0.02%-0.04% of P and the balance Fe powder. By adoption of the welding material composition, production efficiency can be improved by 3-5 times, and the cost is reduced by 50%-60% compared with that of imported welding materials of the same kind.

The invention relates to a high-deposition efficiency and high-welding speed dual-tungsten electrode TIG (Tungsten Inert Gas) welding method for a narrow gap, and belongs to the technical field of TIGwelding. Two different welding guns: an axisymmetrical static tungsten electrode welding gun and a non-axisymmetrical rotating tungsten electrode welding gun, are employed; the welding method comprises the following steps of firstly forming a U-shaped groove in a workpiece, and performing pretreatment on the groove; arranging the two welding guns front and back in a welding direction, and adjusting a posture of each of the two welding guns; enabling distance from one of the two welding gun to the workpiece and distance from the other welding gun to the workpiece to be equal; setting each of welding machines to be in an advanced gas feed mode, centering the welding guns, setting each of wire feeding mechanisms to be in a delayed wire feed mode and an advanced wire drawing mode, and firstlyperforming advanced heating premelting on a weldment; and turning a tungsten electrode of a second welding gun by a motor control box switch of the second welding gun before arc striking, wherein direct current welding is employed. During welding, arc striking is performed on the two welding guns simultaneously for welding, and thus, the front face of a weld joint can be formed well and has no defects: undercuts and the like; welding deposition efficiency and welding speed are obviously increased, and dual-tungsten electrode TIG high-speed welding of the narrow gap with good sidewall fusion degree can be performed.

The invention discloses elective etching solution of nickel or nickel alloy, and a preparation method and application thereof. The etching solution is prepared from the following ingredients in parts by weight: ferric trichloride, ferric trifluoroacetylacetonate, sulfamic acid, hexanedioic acid, gamma-3-aminopropyltriethoxysilane, potassium thiosulfate, hydrofluoric acid, imidazoline ammonium salt and deionized water. The etching solution provided by the invention has a proper etching speed for the nickel or nickel alloy, hardly corrodes copper, and is high in selectivity. In addition, an etched copper plate has a light surface, is free from sediments, is smooth and is free from lateral erosion.