A zinc foil has a zinc crystal grain size of 0.2 μm or more and 50 μm or less. The zinc foil preferably includes: a base metal containing zinc; and a metal element other than zinc. The metal element preferably includes at least one selected from the group consisting of bismuth, indium, magnesium, calcium, gallium, tin, barium, strontium, silver, and manganese. It is also preferable that the content of the metal element is 10 ppm or more and 10000 ppm or less in terms of mass. It is also preferable that the zinc foil has an apparent density of 3 g/cm.sup.3 or more and 7 g/cm.sup.3 or less. The apparent density is based on contour measurement.

The present disclosure provides electrolyte solutions for electrodeposition of zinc-manganese alloys, methods of forming electrolyte solutions, methods of electrodepositing zinc-manganese alloys, and multilayered zinc-manganese alloys. An electrolyte solution for electroplating can include a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde. An electrolyte solution can be formed by dissolving a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde in water or an aqueous solution. Electrodepositing zinc-manganese alloys on a substrate can include introducing a cathode and an anode into an electrolyte solution comprising a metal salt, boric acid, an alkali metal chloride, polyethylene glycol, and a hydroxy benzaldehyde. Electrodepositing can further include passing a current between the cathode and the anode through the electrolyte solution to deposit zinc and manganese onto the cathode.

An anti-corrosion terminal material including a base material made of copper or copper alloy and a coating film laminated on the base material: the coating film includes: a first coating film, provided with a zinc layer made of zinc alloy and a tin layer made of tin or tin alloy which are laminated in this order, and formed at a planned core contact part; and a second coating film including the tin layer but not comprising the zinc layer, which is provided at a planned contact part being a contact part when the terminal is formed: and the zinc layer has a thickness not less than 0.1 μm and not more than 5.0 μm and zinc concentration not less than 30% by mass and not more than 95% by mass, and has any one or more of nickel, iron, manganese, molybdenum, cobalt, cadmium, lead and tin as a balance.

Electrolyte solutions for electrodeposition of zinc alloys and methods of electrodepositing zinc-iron alloys. An electrolyte solution for electroplating can include an alkali metal hydroxide, a zinc salt, a condensation polymer of epichlorohydrin, a quaternary amine, an aliphatic amine, a polyhydroxy alcohol, an aromatic organic acid and/or salts thereof, an amino alcohol, a bisphosphonic acid and/or salts thereof, an iron salt, an alkali metal gluconate, and an amine-based chelating agent. Electrodepositing zinc alloys on a substrate can include introducing a cathode and an anode into an electrolyte solution comprising an alkali metal hydroxide, a zinc salt, a condensation polymer of epichlorohydrin, a quaternary amine, an aliphatic amine, a polyhydroxy alcohol, an aromatic organic acid and/or salts thereof, an amino alcohol, a bisphosphonic acid and/or salts thereof, an iron salt, an alkali metal gluconate, and an amine-based chelating agent.

A manufacturing method of copper foil and circuit board assembly for high frequency transmission are provided. Firstly, a raw copper foil having a predetermined surface is produced by an electrolyzing process. Subsequently, a roughened layer including a plurality of copper particles is formed on the predetermined surface by an arsenic-free electrolytic roughening treatment and an arsenic-free electrolytic surface protection treatment. Thereafter, a surface treatment layer is formed on the roughened layer, and the roughened layer is made of a material which includes at least one kind of non-copper metal elements and the concentration of the non-copper metal elements is smaller than 400 ppm. By controlling the concentration of the non-copper elements, the resistance of the copper foil can be reduced.

A metal porous body having a three-dimensional network structure, includes: a framework forming the three-dimensional network structure; and a coating layer having fine pores and coating the framework, the three-dimensional network structure including a rib and a node connecting a plurality of ribs, the framework including an alkali-resistant first metal, the fine pores having an average fine pore diameter of 10 nm or more and 1 μm or less, the coating layer including an alkali-resistant second metal and optionally including an alkali-soluble metal, the alkali-soluble metal being contained at a proportion of 0% by mass or more and 30% by mass or less with reference to a total mass of the framework and the coating layer.

Embodiments relate to nanoporous copper interconnects on a first body for electrically connecting to a second body. To fabricate the nanoporous copper interconnect, a zinc-copper alloy is deposited on recesses on the surface of the first body, and then the zinc is removed from the zinc-copper alloy to obtain nanoporous copper. The first body and the second body can be attached using bonding between oxide surfaces of the two bodies or be provided with underfill between the two bodies. The nanoporous copper electrically connects to an active layer or electrical components of the first body and the second bodies. Using nanoporous copper as interconnects is advantageous, among other reasons, because it can be formed at a low temperature, it is compatible with a standard complementary metal-oxide-semiconductor (CMOS) process, it provides good electrical conductivity, and it is less likely to cause issues due to migration of material.

A method of forming a multilayered zinc alloy coating comprises steps of providing a bath of an aqueous electrolyte including zinc and a second electrodepositable component in an electrolytic cell having an anode and a cathode; applying a current or voltage between the anode and the cathode; modulating the applied current or voltage over time between at least two current or voltage values to thereby modulate the current density over multiple cycles between at least two current density values, wherein a first current density value is in a range of 0.3 to less than 2 A/dm.sup.2 and a second current density value is higher than the first current density value and is in a range of 0.6 to less than 5 A/dm.sup.2; and controlling the modulation of the applied current or voltage to obtain a multilayered structure having multiple layers of one or more of alternating proportions of the second component, alternating corrosion potential, alternating grain size, and alternating grain orientation, wherein one or more of the multiple layers has a thickness in the range of 1 to 10 μm.

A steel sheet for a fuel tank includes: a Zn—Ni alloy plated layer which is placed on one surface or each of both surfaces of a base metal and formed on at least one surface; and an inorganic chromate-free chemical conversion coating film which is placed over the Zn—Ni alloy plated layer. The Zn—Ni alloy plated layer has a crack starting from an interface between the Zn—Ni alloy plated layer and the inorganic chromate-free chemical conversion coating film and reaching an interface between the Zn—Ni alloy plated layer and the steel sheet, and a water contact angle on a surface of the inorganic chromate-free chemical conversion coating film is more than or equal to 50 degrees.

A steel sheet coated with a coating comprising from 10 to 40% of nickel, the balance being zinc, such steel sheet having a microstructure comprising from 1 to 50% of residual austenite, from 1 to 60% of martensite and optionally at least one element chosen from: bainite, ferrite, cementite and pearlite, and the following chemical composition in weight: 0.10<C<0.50%, 1.0<Mn<5.0%, 0.7<Si<3.0%, 0.05<Al<1.0%, 0.75<(Si+Al)<3.0% and on a purely optional basis, one or more elements such as Nb≤0.5%, B≤0.005%, Cr≤1.0%, Mo≤0.50%, Ni≤1.0%, Ti≤0.5%, the remainder of the composition making up of iron and inevitable impurities resulting from the elaboration.