A nuclear fuel rod comprises nuclear fuel contained in a cladding, the cladding comprising a tube and two plugs, the tube extending along a central axis and having two ends, each plug being attached to a corresponding end of the tube by sealing the end of the tube. The tube is covered by a tube coating extending over the entire length of the tube from one end of the tube to the other.

System and method of manufacturing high-strength bonded metal sheets for a battery cell are provided. The method comprises providing a stackup comprising a first metal sheet and a second metal sheet. The first and second metal sheets are separated by a first coating layer. The first coating layer comprises nickel-phosphide. The first metal sheet includes a first material of a first melting point and the second metal sheet includes a second material of a second melting point. The first coating layer including a third material of a third melting point. The method further comprises heating the stackup to allow crystallization of nickel in the first coating layer and remove the residual nickel-phosphide defining an enhanced coating layer. The enhanced coating layer comprises crystallized nickel for high-strength solid state bonding of the first and second metal sheets to the enhanced coating layer.

A method of joining a multiple member work-piece includes providing a first steel work-piece having a first electrical resistivity and a second steel work-piece having a second electrical resistivity that is lower than the first electrical resistivity. A third material is disposed in contact with the second steel work-piece. The third material has an electrical resistivity that is greater than the second electrical resistivity. The method includes resistance welding the first and second work-pieces together. The third material may be in the form of a rivet, a third work-piece, or a coating material disposed between the first and second work-pieces. A bonded assembly includes steel members and a third material being bonded together, wherein the electrical resistivity of the second member is lower than the electrical resistivity of the first member, and the third material has an electrical resistivity that is greater than the electrical resistivity of the second member.

System and method of manufacturing high-strength bonded metal sheets for a battery cell are provided. The method comprises providing a stackup comprising a first metal sheet and a second metal sheet. The first and second metal sheets are separated by a first coating layer. The first coating layer comprises nickel-phosphide. The first metal sheet includes a first material of a first melting point and the second metal sheet includes a second material of a second melting point. The first coating layer including a third material of a third melting point. The method further comprises heating the stackup to allow crystallization of nickel in the first coating layer and remove the residual nickel-phosphide defining an enhanced coating layer. The enhanced coating layer comprises crystallized nickel for high-strength solid state bonding of the first and second metal sheets to the enhanced coating layer.

Provided is a resistance spot welding method. The resistance spot welding method for joining a sheet set including a plurality of lapped steel sheets includes: holding the sheet set between a pair of electrodes; and energizing the sheet set under application of electrode force to thereby join the steel sheets together. At least one of the plurality of lapped steel sheets is a surface-treated steel sheet including a metal coating layer on a surface thereof. The energizing includes: a primary energizing step of performing energization to form a nugget portion; a non-energizing step in which, after the primary energizing step, the energization is suspended for an energization suspension time Tc (cycles); and a secondary energizing step of, after the non-energizing step, performing energization for reheating while the nugget portion is prevented from growing. During the energizing, the relations of a particular formula are satisfied.

A workpiece of Ti or a Ti alloy includes a surface with a coating layer of titanium nitride. A region of the surface includes a connection zone of a Ti—N solid solution alloy. A second Ti or Ti alloy workpiece is contacted with the connection zone, and a weld joint is formed across the connection zone with a resistance welding process. The weld joint extends into the first Ti workpiece and the second Ti workpiece.

A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process uniformly preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A multi-tiered weld program that is effective in resistance spot welding of dissimilar materials is disclosed. The process is repeatable across a multitude of grades/thicknesses, and number of sheets of conductive materials, and is possible to perform with traditional weld tooling and electrodes. Different size/different material/different contact face geometries weld surfaces are used to balance thermal properties of the materials, and the process is designed to create a small, consistent Intermetallic Compound (IMC) that is effective in holding two different conductive materials together with a high level of strength that is suitable for industrial mass production. The multi-tiered resistance spot weld process preheats, welds, and cools the samples to control the formation of the IMC that is formed therein.

A welding process used in a method of manufacturing a steel sheet assembly includes spot welding steel sheets performed for a heat time of 0.08 seconds or more using a convex electrode with a tip radius of curvature of 20 mm or more or a flat electrode such that the weld force F (kN) for initial 0.03 seconds of the heat time satisfies formula: F<0.00125×(1+0.75×t.sub.all)+3 where TS (MPa) denotes an average strength of the steel sheets and represents a weighted mean value of a thickness of each of the steel sheets, and t.sub.all (mm) denotes a total thickness of the steel sheets (the sum of the thicknesses of the steel sheets).

Provided is a method of manufacturing a joined member that is manufactured by applying resistance welding to a workpiece. The workpiece is provided with plating layers on sides to be in contact with electrodes. In a state in which a first electrode is in contact with a first area in a first plate material that is curved along a contour of a leading end of the first electrode and in which a second electrode is in contact with a second area in a second plate material that is curved along a contour of a leading end of the second electrode, energization between the first electrode and the second electrode is started to form a nugget.