Metal powder particles for use in additive manufacturing are made by removing material from the surface of the particles using wet chemical etching to create a nanoscale texturing of the surface, increasing absorptivity by the metal powder particles of incident laser light and maintaining flowability. The nanoscale texturing has sub-wavelength features at laser wavelengths in the range 800-1100 nm. The particles are substantially spherical and have mean diameters in the range 10-70 μm.

A treatment liquid contains orthoperiodic acid and water, and the pH is 11 or more. It is preferable that the content of orthoperiodic acid in the treatment liquid is 0.01% to 5% by mass with respect to the total mass of the treatment liquid.

A treatment liquid contains orthoperiodic acid and water, and the pH is 11 or more. It is preferable that the content of orthoperiodic acid in the treatment liquid is 0.01% to 5% by mass with respect to the total mass of the treatment liquid.

A surface-treated metallic workpiece of titanium and/or titanium alloys with titanium as the main constituent and/or nickel-titanium alloys and also nitinol, wherein on the treated surface the metal is free from inclusions, precipitates of other metals, accumulations of alkali metals, alkaline earth metals and/or aluminium, intermetallic phases, and/or mechanically highly defect-rich regions, and the surface has a first roughness and a second roughness, wherein the first roughness is provided by depressions in the form of pores, the pores having a diameter in the range between 0.5 and 50 μm—being open in the direction of the surface and closed in the direction of the workpiece, and at least some of the pores having an undercut, and the second roughness is provided by randomly distributed elevations and depressions in the range of 100 nm and less. The invention also relates to a production process for a surface-treated workpiece.

A surface-treated metallic workpiece of titanium and/or titanium alloys with titanium as the main constituent and/or nickel-titanium alloys and also nitinol, wherein on the treated surface the metal is free from inclusions, precipitates of other metals, accumulations of alkali metals, alkaline earth metals and/or aluminium, intermetallic phases, and/or mechanically highly defect-rich regions, and the surface has a first roughness and a second roughness, wherein the first roughness is provided by depressions in the form of pores, the pores having a diameter in the range between 0.5 and 50 μm—being open in the direction of the surface and closed in the direction of the workpiece, and at least some of the pores having an undercut, and the second roughness is provided by randomly distributed elevations and depressions in the range of 100 nm and less. The invention also relates to a production process for a surface-treated workpiece.

An object is to provide a ruthenium removal composition capable of dissolving Ru while suppressing dissolution of CoFeB, and a method of producing a magnetoresistive random access memory (MRAM) using the same. A ruthenium removal composition of the present invention contains orthoperiodic acid and water, and the pH is 11 or more. It is preferable that the content of orthoperiodic acid in the ruthenium removal composition is 0.01% to 5% by mass with respect to the total mass of the composition.

An object is to provide a ruthenium removal composition capable of dissolving Ru while suppressing dissolution of CoFeB, and a method of producing a magnetoresistive random access memory (MRAM) using the same. A ruthenium removal composition of the present invention contains orthoperiodic acid and water, and the pH is 11 or more. It is preferable that the content of orthoperiodic acid in the ruthenium removal composition is 0.01% to 5% by mass with respect to the total mass of the composition.

The present invention relates to a HEA foam prepared by selective dissolution of a second phase within a two-phase separating alloy comprising the HEA and a manufacturing method thereof. The manufacturing method of the HEA foam of the present invention has the effect of preparing a novel HEA foam, which was not available in the past, by leaving only a first phase after manufacturing a two-phase separating alloy comprising a first phase by HEA, wherein at least 3 metal elements act as a common solvent.

Furthermore, the HEA foam of the present invention has a structure, wherein pores are distributed inside the HEA, in which at least 3 metal elements act as a common solvent. By adding a functional characteristic of low heat conductivity, etc., to the existing high strength characteristic of HEA, the HEA foam of the present invention can exhibit a complex effect by the combination of the two particular effects, thereby being capable of exhibiting excellent physical characteristics.

A method of forming an implant to be implanted into living bone is disclosed. The method comprises the act of roughening at least a portion of the implant surface to produce a microscale roughened surface. The method further comprises the act of immersing the microscale roughened surface into a solution containing hydrogen peroxide and a basic solution to produce a nanoscale roughened surface consisting of nanopitting superimposed on the microscale roughened surface. The nanoscale roughened surface has a property that promotes osseointegration.

A method of forming an implant to be implanted into living bone is disclosed. The method comprises the act of roughening at least a portion of the implant surface to produce a microscale roughened surface. The method further comprises the act of immersing the microscale roughened surface into a solution containing hydrogen peroxide and a basic solution to produce a nanoscale roughened surface consisting of nanopitting superimposed on the microscale roughened surface. The nanoscale roughened surface has a property that promotes osseointegration.