An electrode and a device for resistance spot welding are capable of preventing an occurrence of a surface spatter by using magnetism. The electrode may include a shank and a welding tip mounted to an end of the shank. A magnetic unit is installed on an outer peripheral surface of the shank to form a magnetic field and to form a Lorentz force in a direction of rotation along a circumferential direction of the shank by the magnetic field and a current flowing through the shank.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A welding gun for resistance spot welding includes a first electrode; a second electrode having a fixed part and a movable part movable toward the first electrode, an electromechanical linear actuator of the first electrode fixedly attached to the fixed part of the second electrode and having a first force sensor and a rod connected to the first electrode; an electromechanical linear actuator of the movable part of the second electrode having a housing, an electric motor, an inverted roller-screw gear transforming rotary motor movement into rod translation, a position sensor determining a position of the movable part of the second electrode, and a bevel gear transferring electric motor rotation to the inverted roller-screw gear. The rod of the electromechanical linear actuator is connected to the movable part of the second electrode. The welding gun further includes a second force sensor configured to measure force on the second electrode.

The electrode for welding sheets of steel or aluminum, with a conductivity greater than or equal to 90% IACS and made of an alloy including, by weight based on the total weight of the alloy, chromium in a proportion higher than or equal to 0.1% and lower than 0.4%, between 0.02 and 0.04% of zirconium, lower than 0.015% of phosphorus, the remainder being copper and less than 0.1% of unavoidable impurities. The electrode structure advantageously includes incoherent chromium precipitates, more than 90% of which have a projected surface area of less than 1 μm.sup.2, the precipitates having a size of between 10 and 50 nm. The electrode has a fiber structure of radial fibers, each fiber having a thickness of less than 1 mm and a substantially central fibreless region that has a diameter of less than 5 mm. The invention also relates to a method for producing the electrode.

The electrode for welding sheets of steel or aluminum, with a conductivity greater than or equal to 90% IACS and made of an alloy including, by weight based on the total weight of the alloy, chromium in a proportion higher than or equal to 0.1% and lower than 0.4%, between 0.02 and 0.04% of zirconium, lower than 0.015% of phosphorus, the remainder being copper and less than 0.1% of unavoidable impurities. The electrode structure advantageously includes incoherent chromium precipitates, more than 90% of which have a projected surface area of less than 1 μm.sup.2, the precipitates having a size of between 10 and 50 nm. The electrode has a fiber structure of radial fibers, each fiber having a thickness of less than 1 mm and a substantially central fibreless region that has a diameter of less than 5 mm. The invention also relates to a method for producing the electrode.

A metal joined body has an iron base body and an aluminum base body that are joined together via a joint layer. The joint layer has a first layer composed of a first intermetallic compound formed on the iron base body side and a second layer composed of a second intermetallic compound formed on the aluminum base body side. The first layer has one or more first protrusions that merge integrally into the iron base body and extend in a pile shape into the first intermetallic compound. The second layer may have one or more second protrusions that are composed of a second intermetallic compound and extend in a columnar shape into the aluminum base body. The first intermetallic compound may contain Al.sub.5Fe.sub.2, and the second intermetallic compound may contain Al.sub.3Fe. The total thickness of the first layer and the second layer is, for example, 2 to 15 μm.

The present disclosure provides a system for printing a three-dimensional (3D) object. The system may comprise a source of at least one feedstock, a support for supporting at least a portion of the 3D object, a feeder for directing such feedstock from the source towards the support, and a power supply for supplying electrical current. The system may comprise a controller operatively coupled to the power supply. The controller may receive a computational representation of the 3D object. The controller may direct such feedstock through a feeder towards the support and may direct electrical current through such feedstock and into the support. The controller may subject such feedstock to heating such that at least a portion of such feedstock may deposit adjacent to the support. The controller may direct deposition of additional portions adjacent to the support and may direct an additional feedstock through such feeder and subject to heating.

In a coolant drop prevention system (1), a first pipe (4) has a first end connected to a portion of a coolant supply pipe (15) closer to a welding gun (11) than a first stop valve (2). A second pipe (5) has a first end connected to a portion of a coolant discharge pipe (16) closer to the welding gun (11) than a second stop valve (3). A drain pipe (6) has a first end connected to a portion of the coolant discharge pipe (16) farther from the welding gun (11) than the second stop valve (3). A pump unit (7) sucks in coolant from the first pipe (4) and the second pipe (5) and discharges the sucked coolant into the drain pipe (6).

A collet assembly including an actuator and a collet connected to the actuator. The collet assembly is adapted to be installed on a welding electrode holder having an electrode. The collet is moveable by the actuator from an advanced position, in which the collet is adapted to grip a fastener such as a welding rivet, and a retracted position, in which at least a portion of the collet is retracted into the actuator to enable the electrode to engage the fastener for welding to a work piece, and the collet is adapted to release the fastener.

The invention relates to a welding electrode for resistance welding, formed by a welding tool made of a metal, the welding tool having a contact surface that comes into contact with the workpiece to be welded. In order to avoid adhesion between the contact surface and a workpiece made, in particular of aluminum, it is suggested in the invention that the contact surface is made of diamond doped with boron.