Electroplating methods and systems are described that include adding a metal-ion-containing starting solution to a catholyte to increase a metal ion concentration in the catholyte to a first metal ion concentration. The methods and systems further include measuring the metal ion concentration in the catholyte while the metal ions electroplate onto a substrate and the catholyte reaches a second metal ion concentration that is less than the first metal ion concentration. The methods and systems additionally include adding a portion of an anolyte directly to the catholyte when the catholyte reaches the second metal ion concentration. The addition of the portion of the anolyte increases the metal ion concentration in the catholyte to a third metal ion concentration that is greater than or about the first metal ion concentration.

An overlay of a sliding component, such as a sliding component for an engine, may provide a bearing surface against a steel journal, for example. The overlay may include intermetallic particles disposed in a matrix including tin (Sn). The matrix may be formed by electroplating. Examples of intermetallic particles include, but are not limited to, aluminides and nickel aluminides. The matrix may include an electroplated matrix of tin and/or a tin alloy.

A composition comprising a source of metal ions and at least one additive comprising a polyalkyleneimine backbone, said polyalkyleneimine backbone having a molecular weight Mw of from 300 g/mol to 1000000 g/mol, wherein the N hydrogen atoms in the backbone are substituted by a polyoxyalkylene radical and wherein the average number of oxyalkylene units in said polyoxyalkylene radical is from 1.5 to 10 per N—H unit.

A composition comprising a source of metal ions and at least one additive comprising a polyalkyleneimine backbone, said polyalkyleneimine backbone having a molecular weight Mw of from 300 g/mol to 1000000 g/mol, wherein the N hydrogen atoms in the backbone are substituted by a polyoxyalkylene radical and wherein the average number of oxyalkylene units in said polyoxyalkylene radical is from 1.5 to 10 per N—H unit.

The chemical treatment steel sheet includes a steel sheet, a mat finished Sn plating layer that is provided as an upper layer of the steel sheet and is formed of a β-Sn, and a chemical treatment layer that is provided as an upper layer of the Sn plating layer. The Sn plating layer contains the β-Sn of 0.10 g/m.sup.2 to 20.0 g/m.sup.2 in terms of an amount of metal Sn. A crystal orientation index of a (100) plane group of the Sn plating layer is higher than crystal orientation indexes of other crystal orientation planes. The chemical treatment layer includes a Zr compound containing Zr of 0.50 mg/m.sup.2 to 50.0 mg/m.sup.2 in terms of an amount of metal Zr, and a phosphate compound.

A hot-dip coated steel substrate coated with a layer of Sn directly topped by a zinc or an aluminum based coating is provided, the steel substrate having the following chemical composition in weight percent:
0.10≤C≤0.4%,
1.2≤Mn≤6.0%,
0.3≤Si≤2.5%,
Al≤2.0%,
and on a purely optional basis, one or more elements such as
P<0.1%,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, the steel substrate further having between 0.0001 and 0.01% by weight of Sn in the region extending from the steel substrate surface up to 10 μm.

A hot-dip coated steel substrate coated with a layer of Sn directly topped by a zinc or an aluminum based coating is provided, the steel substrate having the following chemical composition in weight percent:
0.10≤C≤0.4%,
1.2≤Mn≤6.0%,
0.3≤Si≤2.5%,
Al≤2.0%,
and on a purely optional basis, one or more elements such as
P<0.1%,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, the steel substrate further having between 0.0001 and 0.01% by weight of Sn in the region extending from the steel substrate surface up to 10 μm.

To provide a Sn-based plated steel sheet capable of exhibiting superior corrosion resistance, yellowing resistance, coating film adhesiveness, and sulphide stain resistance without using a chromate film. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein the Sn-based plating layer contains 1.0 g/m.sup.2 to 15.0 g/m.sup.2 of Sn per side in terms of metal Sn, the coating layer contains zirconium oxide, and a content of the zirconium oxide is 1.0 mg/m.sup.2 to 10.0 mg/m.sup.2 per side in terms of metal Zr, the zirconium oxide includes zirconium oxide with an amorphous structure, and a crystalline layer whose main component is zirconium oxide with a crystalline structure is present on an upper layer of the zirconium oxide with the amorphous structure.

To provide a Sn-based plated steel sheet capable of exhibiting superior corrosion resistance, yellowing resistance, coating film adhesiveness, and sulphide stain resistance without using a chromate film. A Sn-based plated steel sheet of the present invention includes: a steel sheet; a Sn-based plating layer located on at least one surface of the steel sheet; and a coating layer located on the Sn-based plating layer, wherein the Sn-based plating layer contains 1.0 g/m.sup.2 to 15.0 g/m.sup.2 of Sn per side in terms of metal Sn, the coating layer contains zirconium oxide, and a content of the zirconium oxide is 1.0 mg/m.sup.2 to 10.0 mg/m.sup.2 per side in terms of metal Zr, the zirconium oxide includes zirconium oxide with an amorphous structure, and a crystalline layer whose main component is zirconium oxide with a crystalline structure is present on an upper layer of the zirconium oxide with the amorphous structure.

Disclosed are pre-wetting apparatus designs and methods. In some embodiments, a pre-wetting apparatus includes a degasser, a process chamber, and a controller. The process chamber includes a wafer holder configured to hold a wafer substrate, a vacuum port configured to allow formation of a subatmospheric pressure in the process chamber, and a fluid inlet coupled to the degasser and configured to deliver a degassed pre-wetting fluid onto the wafer substrate at a velocity of at least about 7 meters per second whereby particles on the wafer substrate are dislodged and at a flow rate whereby dislodged particles are removed from the wafer substrate. The controller includes program instructions for forming a wetting layer on the wafer substrate in the process chamber by contacting the wafer substrate with the degassed pre-wetting fluid admitted through the fluid inlet at a flow rate of at least about 0.4 liters per minute.