Electric resistance welding

About: Electric resistance welding is a research topic. Over the lifetime, 16761 publications have been published within this topic receiving 154851 citations.

Method of coupling plastic pipes by welding and a connection piece for coupling same

Abstract: The coupling of two tubular elements is achieved by welding them together by energization of an electrical resistance element, the one element comprising a male end, the other a socket end. The coupling operation is carried out by means of a composite connecting piece comprising two rings which are fitted on one another, one acting as a support for a bifilar electrical resistance element and the other as a sheath. The electrical resistance element is thus uniformly coated in plastic material and is accurately centered, thereby ensuring uniform heating and welding. This coupling method is for use in coupling discharge pipelines for waste water and rain water and for conduits for industrial fluids.

Optimization of operator and physical parameters for laser welding of dental materials.

Abstract: Objective Interactions between lasers and materials are very complex phenomena. The success of laser welding procedures in dental metals depends on the operator's control of many parameters. The aims of this study were to evaluate factors relating to the operator's dexterity and the choice of the welding parameters (power, pulse duration and therefore energy), which are recognized determinants of weld quality. Design In vitro laboratory study. Materials and methods FeNiCr dental drawn wires were chosen for these experiments because their properties are well known. Different diameters of wires were laser welded, then tested in tension and compared to the control material as extruded, in order to evaluate the quality of the welding. Scanning electron microscopy of the fractured zone and micrograph observations perpendicular and parallel to the wire axis were also conducted in order to analyse the depth penetration and the quality of the microstructure. Additionally, the micro-hardness (Vickers type) was measured both in the welded and the heat-affected zones and then compared to the non-welded alloy. Results Adequate combination of energy and pulse duration with the power set in the range between 0.8 to 1 kW appears to improve penetration depth of the laser beam and success of the welding procedure. Operator skill is also an important variable. Conclusion The variation in laser weld quality in dental FeNiCr wires attributable to operator skill can be minimized by optimization of the physical welding parameters.

Aluminum alloy brazing sheet for heat exchanger

Abstract: An aluminum alloy brazing sheet for heat exchangers has a core, a sacrificial material formed on one side of the core, and a brazing filler metal formed on the other side of core. The core is made of an aluminum alloy containing predetermined amounts of Si, Cu, and Mn, the balance being Al and unavoidable impurities. The sacrificial material is made of an aluminum alloy containing predetermined amounts of Si, Zn, and Mg with the balance of Al and unavoidable impurities. The brazing filler metal is made of an aluminum alloy. The aluminum alloy brazing sheet for heat exchangers has a work hardening exponent n of not less than 0.05. The aluminum alloy brazing sheet for heat exchangers has excellent strength and corrosion resistance even when it is formed into a thin material and also has excellent high frequency weldability and weld cracking resistance during electric resistance welding (high frequency welding properties).

Electrode sticking during micro-resistance welding of thin metal sheets

Abstract: The electrode sticking mechanism and factors affecting the sticking, including welding current, weld time, electrode tip coating, electrode force and electrode spacing, were studied during micro-resistance welding of very thin nickel-plated steel to nickel sheets in the assembly of a cell-phone battery package. The results indicated that electrode sticking was caused by local metallurgical bonding between the electrode and the nickel-plated steel sheet. The sticking force was proportional to the total area of the local bonds and to the bonding strength between the electrode and sheet. Reducing welding current and weld time, and increasing electrode force and electrode spacing were found to reduce electrode sticking. Welding electrodes with tips coated with TiC metal matrix composite were tried as an alternative to the regular CuCrZr electrode and were found to be more resistant to sticking.