A method for creating a chrome-plated surface having a matte finish that typically includes: controlling a resistance of a current bridge circuit; depositing a first chromium layer on a substrate positioned in a chromium bath, wherein the first chromium layer is deposited by supplying current from a power source that is electrically connected to the substrate and to anodes positioned in the chromium bath; etching the first chromium layer by engaging a current bridge that closes the current bridge circuit; depositing a first intermediate chromium layer, wherein the first intermediate chromium layer is deposited by supplying current from the power source; etching the first intermediate chromium layer, wherein the first intermediate chromium layer is etched by engaging the current bridge; and depositing a final chromium layer, wherein the final chromium layer is deposited by supplying current from the power source.

A method for creating a chrome-plated surface having a matte finish that typically includes: controlling a resistance of a current bridge circuit; depositing a first chromium layer on a substrate positioned in a chromium bath, wherein the first chromium layer is deposited by supplying current from a power source that is electrically connected to the substrate and to anodes positioned in the chromium bath; etching the first chromium layer by engaging a current bridge that closes the current bridge circuit; depositing a first intermediate chromium layer, wherein the first intermediate chromium layer is deposited by supplying current from the power source; etching the first intermediate chromium layer, wherein the first intermediate chromium layer is etched by engaging the current bridge; and depositing a final chromium layer, wherein the final chromium layer is deposited by supplying current from the power source.

Methods and systems of electrochemically machining are provided. The methods may include applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field. The electrochemical machining system may include a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel within the at least one bias electrode. The method may further include applying at least one second potential to the at least one bias electrode. The method may further include delivering a charged electrolyte solution through the at least one fluid delivery channel into the electrolyte solution. Applying at least one second potential and the delivering the charged electrolyte solution generates at least one secondary electric field adjacent to the primary electric field and quenches at least one location of the primary electric field.

Methods and systems of electrochemically machining are provided. The methods may include applying a first potential to a tool electrode of an electrochemical machining system to generate a primary electric field. The electrochemical machining system may include a workpiece opposite the tool electrode, at least one bias electrode, and at least one fluid delivery channel within the at least one bias electrode. The method may further include applying at least one second potential to the at least one bias electrode. The method may further include delivering a charged electrolyte solution through the at least one fluid delivery channel into the electrolyte solution. Applying at least one second potential and the delivering the charged electrolyte solution generates at least one secondary electric field adjacent to the primary electric field and quenches at least one location of the primary electric field.

Methods and systems of electrochemically machining a component are provided. The method may include applying two or more potentials to a tool electrode comprising an array of two or more individual electrodes to generate two or more electric fields in between the tool electrode and a workpiece opposite of the tool electrode, wherein each of the two or more electric fields is generated by one of the array of two or more individual electrodes.

Methods and systems of electrochemically machining a component are provided. The method may include applying two or more potentials to a tool electrode comprising an array of two or more individual electrodes to generate two or more electric fields in between the tool electrode and a workpiece opposite of the tool electrode, wherein each of the two or more electric fields is generated by one of the array of two or more individual electrodes.

A steel sheet for cans has, on the surface thereof, in order from the steel sheet side, a chromium metal layer and a hydrous chromium oxide layer. The chromium metal layer is deposited in an amount of 50-200 mg/m.sup.2, and the hydrous chromium oxide layer is deposited in an amount of 3-15 mg/m.sup.2 in terms of chromium. The chromium metal layer includes: a flat chromium metal layer that has a thickness of at least 7 nm; and a granular chromium metal layer that includes granular protrusions that are formed on the surface of the flat chromium metal layer. The maximum grain size of the granular protrusions is 150 nm or smaller. The number density of the granular protrusions per unit area is 10/m.sup.2 or higher.

A steel sheet for cans has, on the surface thereof, in order from the steel sheet side, a chromium metal layer and a hydrous chromium oxide layer. The chromium metal layer is deposited in an amount of 50-200 mg/m.sup.2, and the hydrous chromium oxide layer is deposited in an amount of 3-15 mg/m.sup.2 in terms of chromium. The chromium metal layer includes: a flat chromium metal layer that has a thickness of at least 7 nm; and a granular chromium metal layer that includes granular protrusions that are formed on the surface of the flat chromium metal layer. The maximum grain size of the granular protrusions is 150 nm or smaller. The number density of the granular protrusions per unit area is 10/m.sup.2 or higher.

A metal product capable of firmly combing a component of different materials with the metal to form a metal composite article includes a metal substrate. One or more surfaces of the metal substrate have a hole therein, the hole decreases in size towards an opening on the surface. A is the longest distance between any two points on a periphery of the opening. A plane of the opening is defined by the two points and a third point on the periphery of the opening. A periphery of an inner wall of the hole is defined on an intersection of the section plane and the inner wall of the hole. B is the longest distance between any two points on the periphery of the inner wall of the hole, and B is greater than A. The disclosure further provides a metal composite article and a method of manufacture.

A metal product capable of firmly combing a component of different materials with the metal to form a metal composite article includes a metal substrate. One or more surfaces of the metal substrate have a hole therein, the hole decreases in size towards an opening on the surface. A is the longest distance between any two points on a periphery of the opening. A plane of the opening is defined by the two points and a third point on the periphery of the opening. A periphery of an inner wall of the hole is defined on an intersection of the section plane and the inner wall of the hole. B is the longest distance between any two points on the periphery of the inner wall of the hole, and B is greater than A. The disclosure further provides a metal composite article and a method of manufacture.