A polishing method for an inner wall of a hollow metal part, including: firstly, placing a coaxial cathode in an inner hole of a metal part when a metal part model is designed, and printing the metal part model and the coaxial cathode together; then, sealing two ends of an inner hole cavity of the metal part by using a light curing part, fixing the coaxial cathode, filling the cavity with a polishing solution, and performing polishing treatment by using an electrochemical polishing method; and finally, reversing an electrode to break the coaxial cathode and take out the broken coaxial cathode to obtain a polished metal part. The polishing of a complex-shaped inner hole of a 3D-printed metal part is realized, the defect that an inner hole of a 3D-printed metal part with a complex-shaped hollow part cannot be polished by using a traditional machining method is overcome, the problem that an inner wall of a metal part polished by using an electrochemical method is non-uniform is solved, the surface quality of the inner hole of the 3D-printed metal part with the complex-shaped hollow part is improved, and the application prospect and postprocessing technology of the 3D-printed metal part are expanded.

Systems and methods for regulating hydrogen concentration in structural materials by electrochemically controlling hydrogen desorption to promote recovery from hydrogen embrittlement are disclosed. Embrittled material can be exposed to an electrolyte and a counter electrode to set up a potential across the material to induce the electrochemical oxidation of atomic hydrogen (H) in the surface of the material. Oxidation reduces hydrogen concentration near the surface, increases hydrogen diffusion toward the surface, and eventually accelerates hydrogen desorption through and out of the material. In some embodiments, a catalyst can be applied to the surface of the material to return the material to its original state before embrittlement.

Systems and methods for regulating hydrogen concentration in structural materials by electrochemically controlling hydrogen desorption to promote recovery from hydrogen embrittlement are disclosed. Embrittled material can be exposed to an electrolyte and a counter electrode to set up a potential across the material to induce the electrochemical oxidation of atomic hydrogen (H) in the surface of the material. Oxidation reduces hydrogen concentration near the surface, increases hydrogen diffusion toward the surface, and eventually accelerates hydrogen desorption through and out of the material. In some embodiments, a catalyst can be applied to the surface of the material to return the material to its original state before embrittlement.

A metal-assisted chemical imprinting stamp includes a porous polymer substrate and a noble metal coating formed directly on the porous polymer substrate. Fabricating the metal-assisted chemical imprinting stamp includes providing a porous polymer substrate, and disposing a noble metal on the porous polymer substrate. Metal-assisted chemical imprinting includes positioning a silicon substrate in an etching solution, contacting a surface of the silicon substrate with a stamp comprising a noble metal layer on a surface of a porous polymer substrate, and separating the silicon substrate from the stamp to yield a pattern corresponding to the noble metal layer on the silicon substrate.

A metal-assisted chemical imprinting stamp includes a porous polymer substrate and a noble metal coating formed directly on the porous polymer substrate. Fabricating the metal-assisted chemical imprinting stamp includes providing a porous polymer substrate, and disposing a noble metal on the porous polymer substrate. Metal-assisted chemical imprinting includes positioning a silicon substrate in an etching solution, contacting a surface of the silicon substrate with a stamp comprising a noble metal layer on a surface of a porous polymer substrate, and separating the silicon substrate from the stamp to yield a pattern corresponding to the noble metal layer on the silicon substrate.

Electrochemical analysis method and system for monitoring and controlling the quality of electrochemical deposition and/or plating processes. The method uses a fingerprinting analysis method of an output signal to indicate whether the chemistry and/or process is operating in the normally expected range and utilizes one or more substrates as working electrode(s) and a) whereby the potential between the one or more working electrodes and one or more reference electrodes is analyzed to provide an output signal fingerprint which is represented as potential difference as a function of time or b) the input power of a process power supply to provide input energy in the form of current and/or potential between the working electrode(s) and a counter-electrode whereby the method utilizes the potential between the one or more working electrode(s) and at least one of: one or more reference electrodes; or one or more counter-electrodes; to provide an output signal fingerprint.

Electrochemical analysis method and system for monitoring and controlling the quality of electrochemical deposition and/or plating processes. The method uses a fingerprinting analysis method of an output signal to indicate whether the chemistry and/or process is operating in the normally expected range and utilizes one or more substrates as working electrode(s) and a) whereby the potential between the one or more working electrodes and one or more reference electrodes is analyzed to provide an output signal fingerprint which is represented as potential difference as a function of time or b) the input power of a process power supply to provide input energy in the form of current and/or potential between the working electrode(s) and a counter-electrode whereby the method utilizes the potential between the one or more working electrode(s) and at least one of: one or more reference electrodes; or one or more counter-electrodes; to provide an output signal fingerprint.

Provided are cleaning methods and systems to remove unintended metallic deposits from electroplating apparatuses using reverse current deplating techniques. Such cleaning involves positioning a cleaning (deplating) disk in an electroplating cup similar to a regular processed substrate. The front surface of the cleaning disk includes a corrosion resistant conductive material to form electrical connections to deposits on the cup's surfaces. The disk is sealed in the cup and submerged into a plating solution. A reverse current is then applied to the front conductive surface of the disk to initiate deplating of the deposits. Sealing compression in the cup may change during cleaning to cause different deformation of the lip seal and to form new electrical connections to the deposits. The proposed cleaning may be applied to remove deposits formed during electroplating of alloys, in particular, tin-silver alloys widely used for semiconductor and wafer level packaging.

Provided are cleaning methods and systems to remove unintended metallic deposits from electroplating apparatuses using reverse current deplating techniques. Such cleaning involves positioning a cleaning (deplating) disk in an electroplating cup similar to a regular processed substrate. The front surface of the cleaning disk includes a corrosion resistant conductive material to form electrical connections to deposits on the cup's surfaces. The disk is sealed in the cup and submerged into a plating solution. A reverse current is then applied to the front conductive surface of the disk to initiate deplating of the deposits. Sealing compression in the cup may change during cleaning to cause different deformation of the lip seal and to form new electrical connections to the deposits. The proposed cleaning may be applied to remove deposits formed during electroplating of alloys, in particular, tin-silver alloys widely used for semiconductor and wafer level packaging.

A pickling process of a metallic strip is provided including the steps of: passing said metallic strip through at least a pickling bath being at a temperature between 1 and 100° C., applying an alternating current, having a current density of 1x10.sup.2 to 1x10.sup.5 A.m.sup.−2 of unit surface of said metallic strip to said metallic strip passing through said at least one pickling bath.