An article comprising additively manufactured metal portions is described. The article comprises a first additively manufactured metal portion, and a second additively manufactured metal portion coupled to the first additively manufactured metal portion at a welded joint. The article further comprises a resistive heating material disposed within an interior of the welded joint, the resistive heating material comprising a different material than the first additively manufactured metal portion and the second additively manufactured metal portion.

An induction welder is provided that includes a first lead, a second lead and an induction welding coil. The induction welding coil is electrically coupled with the first lead and the second lead. The induction welding coil is configured as or otherwise includes a conductive element. This conductive element is configured into at least a plurality of loops arranged within a common plane.

An induction welder is provided that includes a first lead, a second lead and an induction welding coil. The induction welding coil is electrically coupled with the first lead and the second lead. The induction welding coil is configured as or otherwise includes a conductive element. This conductive element is configured into at least a plurality of loops arranged within a common plane.

A method includes generating relative movement between a first part and a three-dimensional (3D) printer. The method also includes introducing drops of a liquid metal onto the first part and a second part using the 3D printer. The liquid metal solidifies to join the first part and the second part together.

An article comprising additively manufactured metal portions is described. The article comprises a first additively manufactured metal portion, and a second additively manufactured metal portion coupled to the first additively manufactured metal portion at a welded joint. The article further comprises a resistive heating material disposed within an interior of the welded joint, the resistive heating material comprising a different material than the first additively manufactured metal portion and the second additively manufactured metal portion.

An extruder for a metal material includes a cylinder having a receiving space in which a solid metal material is provided, a nozzle extending from a lower end of the cylinder, an upper coil provided on an outer surface of the cylinder and melting the solid metal material to form a liquid metal material, and a first lower coil provided on an outer surface of the nozzle to control an extruded shape of the liquid metal material.

An extruder for a metal material includes a cylinder having a receiving space in which a solid metal material is provided, a nozzle extending from a lower end of the cylinder, an upper coil provided on an outer surface of the cylinder and melting the solid metal material to form a liquid metal material, and a first lower coil provided on an outer surface of the nozzle to control an extruded shape of the liquid metal material.

A joint of a copper terminal and an aluminum wire, the copper terminal is divided into a connecting part and a functional part connected to the connecting part, and an aluminum wire core of the aluminum wire is connected to the connecting part of the copper terminal. Preferably, the aluminum wire core extends or does not extend to the functional part. The connecting part is a component of the copper terminal that is connected with the aluminum wire, and the functional part is a fixed area of the copper terminal that is configured to connect to a power consumption device.

A method for solid-state, one-shot, butt-welding of multiple coaxial metal pipe subassemblies that have a prescribed annular clearance to allow them to be welded separately yet simultaneously is described. The nested pipes or tubes making up of these subassemblies can thus be joined end to end to form pipelines or wells for oil, gas and geothermal and the like with specific desired advantages over conventional single-wall pipelines or wells casings. The advantages include an ability to monitor the condition of all or selected portions of the pressure envelope constituted by the pipeline or well casing and thereby identify damage with ample advance warning before failure and leakage or major spills occur.

A system used to additively manufacture an object layer-by-layer using direct energy deposition (DED) includes a base where the object is formed, a depositor configured to deposit material layer-by-layer on the base or a previously deposited layer of the object, an energy source configured to selectively direct an energized beam at the material to fuse a new layer of the material to a previously formed layer, and a heating element in contact with at least a portion of the base and configured to supply heat to the base.