A mask includes a mask sheet including an upper surface and a lower surface facing the upper surface, the mask sheet including an opening passing through the upper surface and the lower surface; and a mask frame that supports the mask sheet, the mask sheet includes a protrusion adjacent to the opening and protruding from the lower surface, and a recess adjacent to the protrusion and recessed from the lower surface toward the upper surface of the mask sheet.

The invention relates to a process for laser welding monolithic semi-finished products made of aluminium alloy without filler wire, known to a person skilled in the art under the name “Remote Laser Welding” comprising the following steps:—supplying at least two semi-finished products made of aluminium alloy, at least one of which is a laminated plate with the composition (% by weight): Si: 2.5-14; Fe: 0.05-0.8; Cu: 0.25-1.0; Mg: 0.05-0.8; Mn: ≤0.70; Cr: ≤0.35; Ti: 0.02-0.30; Sr up to 500 ppm; Na up to 200 ppm; Sb up to 0.15%, unavoidable impurities <0.05 each and <0.15 in total, remainder aluminium,—laser welding the semi-finished products made of aluminium alloy without filler wire, which process is known to a person skilled in the art under the name “Remote Laser Welding”. The invention also includes a structural, body-in-white, skin or opening component of a motor vehicle obtained by a process according to the invention.

A method for welding a welded part to a component is carried out as arc ignition welding by use of direct current, having a bias current phase in which an arc is formed between the negatively polarized welded part and the component, and a subsequent main current phase for melting material to the joint. The welded part: a) is a galvanized sphere made of C10C having a roundness G500, wherein the size of any zinc inclusions under the surface of the sphere equals 10 micrometers at maximum, orb) is formed by welding a galvanized sphere made of C10C having a roundness G500, wherein the size of any zinc inclusions under the surface of the sphere equals 10 micrometers at maximum, to a connection element.

Disclosed are a rolled (FeCoNiCrR.sub.n/Al)-2024Al composite panel and a preparation method therefor. The preparation method involves taking pure aluminum as a matrix, adding an FeCoNiCrR.sub.n medium-entropy alloy with a high strength and toughness as an reinforcing phase to prepare an FeCoNiCrR.sub.n/Al composite material, then laminating the FeCoNiCrR.sub.n/Al composite material with aluminum alloy 2024, and preparing the (FeCoNiCrR.sub.n/Al)-2024Al composite board by means of hot-rolling recombination, which solves the problem that high-strength aluminum matrix composites (AMCs) are prone to instantaneous breakability and low ductility, thereby improving the overall performance of the material. The present disclosure adopts microwave sintering (MWS) to fabricate a medium-entropy alloy-reinforced AMC, and adopts hot-roll bonding to fabricate the (FeCoNiCrR.sub.n/Al)-2024Al metal composite panel. The composite panel fabricated by the present disclosure has excellent comprehensive mechanical properties, and has high application values for promoting the application of modern lightweight and high-efficiency industrial materials in aerospace, new energy vehicles, and the like.

A fixture assembly for supporting a plurality of blanks during a shearing and welding operation. The fixture assembly includes a base frame. A rotating frame is rotatably connected to the base frame. A fixed block is fixed to the rotating frame for supporting a first blank. A moveable block is moveably connected to the rotating frame for supporting a second blank. A first clamp is provided for coupling the first blank to the fixed block. A second clamp is provided for coupling the second blank to the moveable block. A vertical actuator is coupled with the rotating frame and configured to move the moveable block in a vertical direction being perpendicular to a plane of the rotating frame for moving the second blank. A horizontal actuator is coupled with the rotating frame and configured to move the moveable block in a horizontal direction.

A composite panel having a plurality of carbon plies, a perforated metallic foil comprising several apertures and being directly secured to the plurality of carbon plies, and a protective layer made from resin reinforced with fibers which is secured to the metallic foil. The perforated metallic foil is embedded in the protective layer through its apertures. A free surface of the protective layer forms a top side of the composite panel. The thickness of the protective layer between the top side of the composite panel and the perforated metallic foil is at least 15 micrometers and the perforated metallic foil has a thickness of not more than 30 micrometers. The plurality of apertures in the aggregate defines an open area of not more than 40% of the surface area and a maximum distance between two opposed points in a perimeter of an aperture is equal to or less than 3 mm.

A plurality of values measured are relatively compared to determine an optical axis deviation direction in which an optical axis of a measurement beam S deviates from a laser beam L. In performing laser welding in the optical axis deviation direction, an irradiation position of the measurement beam S is changed so that the irradiation position of the measurement beam S is moved to a rear side of the center of the optical axis of the laser beam L in the welding direction.

A double-sided friction stir welding method, methods for producing a cold-rolled steel strip and a coated steel strip, a double-sided friction stir welding apparatus, and facilities for producing a cold-rolled steel strip and a coated steel strip. The double-sided friction stir welding method includes pressing two rotating tools, which are disposed on a first surface and a second surface of a butt portion or overlap portion of the steel strips, against the butt portion or overlap portion of steel strips and moving the rotating tools in the welding direction while rotating the rotating tools in opposite directions to each other, so that an unwelded portion of the steel strips is softened by frictional heat generated between the rotating tools and the unwelded portion of the steel strips, and the softened portion is stirred with the rotating tools to generate plastic flow so as to weld the steel strips together.

A double-wall spiral welded pipe includes a first steel belt layer and a second steel belt layer which have equal widths, are arranged in parallel and align with each other; at least two supporting steel bars perpendicular to the first steel belt layer and the second steel belt layer are arranged between the first steel belt layer and the second steel belt layer; the supporting steel bars are arranged on end parts of two sides of the first steel belt layer and the second steel belt layer and extend together with the first steel belt layer and the second steel belt layer; and the first steel belt layer, the second steel belt layer and the supporting steel bars on the end parts of the two sides are mutually welded to form a double-layer composite steel belt with a rectangular section in an extending direction.

A spot welded joint of at least two steel sheets is provided. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≤C≤0.21%, 4.0≤Mn≤7.0%, 0.5≤Al≤3.5%, Si≤2.0%, Ti≤0.2%, V≤0.2%, Nb≤0.2%, P≤0.025%, B≤0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm.sup.2 and containing more than the steel nominal phosphorus content.