August 24, 2020

News Release
Commercialization of a New Copper Alloy Powder Ideal for Laser Additive Manufacturing-- Achieving both high relative density and electro-thermal conductivity -Sanyo Special Steel Co., Ltd has developed and is bringing tomarket a new copper alloy powder ideal for additive
manufacturing.
Pure copper powder is thought to have difficulty obtaining
high-relative-density moldings widely used laser additive
manufacturing methods. Using copper alloy powder enables themanufacture of high-relative-density moldings, even with laser
additive manufacturing. However, this sacrifices copper’s
characteristic electro-thermal conductivity.
Ournewcopper

alloy

powderhasachieved

bothhigh-relative-density additive manufacturing and electro-thermal
conductivity similar to that of pure copper. It can be used for
producing highly functional copper components with complex【Examples of moldings laser additive】

shapes by laser additive manufacturing.
■Difficulties of Using Pure Copper in Laser Additive Manufacturing
Pure copper has excellent electrical and thermal conductivity, and is used in a wide variety of applications. In particular,
electronic and electrical components and heat exchangers are often processed into complex shapes, and additive
manufacturing is expected to help make it easier to create shapes close to the finished product.
However, the laser absorption rate of pure copper is much lower than that of other metals, which makes it difficult for thematerial to absorb thermal energy from the laser. In addition, the high thermal conductivity of copper prevents the heating
required to melt the material, as the heat energy from the laser diffuses rapidly. Therefore, it is difficult to produce
high-relative-density pure copper components by laser additive manufacturing.
The solid solution method, in which other alloy elements are dissolved into the copper matrix, increases the laser
absorption rate of copper. The amount of alloying element that can be dissolved into the copper matrix (the solid-solubilitylimit) is different for each element, so selecting an element with a high solid-solubility limit increases the laser absorption
rate. However, this sacrifices the electrical and thermal conductivity of the moldings.

■Developing a New Copper Alloy Powder Ideal for Laser Additive Manufacturing by Optimizing Alloy Composition
The gas atomization method used in our metal powder production, in which a molten metal is rapidly solidified using ahigh-pressure inert gas (argon, nitrogen, etc.), can even dissolve amounts of alloy elements with low solid-solubility limits
into a copper matrix via supersaturation.
By supersaturating a large amount of alloy element with a low solid-solubility into the copper matrix, the laser absorption
rate is greatly improved. In addition, the electro-thermal conductivity of moldings are restored to a level close to that of purecopper, owing to the supersaturated alloy element being discharged from the copper matrix by heat treatment, and can also
improve strength.
Based on these above concepts, we optimized the alloy composition of copper alloy to be suitable for laser additive
manufacturing. As a result, we developed a new copper alloy powder that has a high laser absorption rate and can achieve
electro-thermal conductivity similar to that of pure copper, and strength exceeding that of pure copper by heat treatment ofmoldings.

■ We Can Supply Copper Alloy Powders to Suit Your Needs
We can provide copper alloy powder to suit yourapplication, such as prioritizing conductivity ordensity/strength. They all can be used to produce
high-relative-density
moldings
bylaser
additivemanufacturing.
The moldings using our copper alloy powder haveapproximately 90% the conductivity of cast pure copper ifusing powder that prioritizes conductivity, and more than 1.5
times the strength of cast pure copper if using powder thatprioritizes density/strength.
Our new copper alloy powder enables high-density laser
additive manufacturing with excellent electro-thermal
conductivity and strength, making it easy to produce
moldings with complex shapes that are difficult withtraditional casting and stretching methods. This is expected
to optimize the shapes of parts such as electronic and electrical components and heat exchangers, as well as create newmarkets in the automotive, aerospace, and medical fields.

In addition to our gas atomization facilities that are capable of producing high-quality spherical metal powders, wehave two state-of-the-art metal 3D printers and a non-destructive inspection system (X-ray CT scan). Besides the copper
alloy powder mentioned above, we are actively working to provide total support for our customers' development, alongwith providing ideal metal powders for additive manufacturing through the development of alloy composition ideal for
additive manufacturing, establishing manufacturing processes that maximize material properties, and utilizing rapidmaterial evaluation systems. We will continue to focus our efforts on developing new products and technologies,
providing solutions that utilize materials and technology in order to improve the competitiveness of our customers.

For inquiries: Sanyo Special Steel Co., Ltd. (Telephone +81-79-235-6002)