TOKYO – TANAKA Kikinzoku Kogyo K.K., a core company of the TANAKA Precious Metals Group, has developed a high-entropy alloy powder composed entirely of precious metals with a fine particle size of 10um or less, high crystallinity and excellent composition uniformity. This is the world’s first high-entropy alloy powder composed entirely of five precious metals: platinum (Pt), palladium (Pd), iridium (Ir), ruthenium (Ru), and rhodium (Rh). TANAKA has established a mass production process and will provide samples in October.
TANAKA has established the five precious metal alloy powders and their production methods used in this product and obtained a basic patent in June 2023[1]. This product’s precious metal alloy powder comprises only five elements that maintain the corrosion resistance, electrical conductivity and other excellent properties of precious metals. They are micro-order[2] alloy powders that are easy to use in industrial applications.
Unlike conventional nano-order precious metal high-entropy alloys, the new alloy is stable due to its large crystallite size, and it satisfies the inherent requirements of alloys, such as improved mechanical strength, corrosion resistance, and controlled thermal expansion. The new alloy powder is expected to improve the functions and properties of precious metal alloys, whose properties vary greatly depending on the composition ratio of the alloy.
The precious metal alloy of this product is in powder form, though it can also be utilized in paste form, which is often used in various circuits and sensors, in addition to modelling using a 3D printer and rod forming (forming rod-shaped material by solidifying powder). Furthermore, high-entropy alloys’ high strength and high heat resistance properties of high-entropy alloys are expected to be utilized in catalysts and conductive films that require high durability, among other applications.
[1] Patent No. 7300565 related to high-entropy alloy powder was granted on June 29, 2023. The precious metal alloy powder in this product is defined as (1) precious metal alloy powder consisting of an alloy of five or more precious metal elements, (2) average particle size of 10µm or less, (3) crystallite size of 60nm or more, and (4) one peak observed in the range of diffraction angle 2θ of 38 to 44° in the X-ray diffraction spectrum.
[2] Order: A term used in physics, engineering, and other fields to roughly express the magnitude of a number. It represents the number of digits or degrees of a unit.
About High-Entropy Alloys
High-entropy alloys are alloys containing five or more elements in equal amounts and are characterized by the absence of major elements that make up most of the alloy. They have been attracting attention as a new category of metallic materials in recent years. Research and development on high-entropy alloys is being conducted worldwide, as the properties of the metals and precious metals contained in these alloys can simultaneously produce properties such as high strength, high heat resistance and the possibility of creating new properties.
