September 29, 2023

News Release
NOVASHAPE® Series – Advanced Metal Powders for Additive Manufacturing

Metal Powders for Die Casting Molds with Higher Thermal Conductivity― Reducing cycle time of die casting and enabling additive manufacturing of large molds ―Sanyo Special Steel has released a new metal powder lineup enabling formation of high-thermal-conductivity diecasting molds by additive manufacturing, thereby reducing the cycle time for die casting and enabling additive
manufacturing of large molds.
When these new metal powders are used with 3D printers to produce die casting molds, effective cooling of themolds during die casting can be achieved. Besides raising productivity by reducing cycle time, use of these powders
can be expected to extend the life of molds. Moreover, the combination of high thermal conductivity and excellent
moldability makes them suitable for additive manufacturing of large molds.
Sanyo will be exhibiting these new powders at the 10th METAL JAPAN Tokyo Expo to be held from October 4 to 6
at Makuhari Messe in Chiba. They will also be introduced at the Autumn Meeting of the Japan Society of Powder andPowder Metallurgy, 2023, to be held from October 19 to 20 at Doshisha University in Kyoto, and will continue to be
actively promoted with a view to expanding their adoption.

Positioning of developed materials

Technical challenges relating to additive
manufacturing of die casting molds

Features of additive manufacturing

Large-size molding and high thermal conductivity

Rapid melting and solidifying in each micro area

SKD61* has a tendency to crack during additive manufacturing, making
it difficult to achieve large-size molding.
Maraging steel has low thermal conductivity, leading to insufficient moldcooling.

• Comprehensive hardening effectivenessDifficult to overcome both these challenges withconventional materials• Inhibition of embrittlement by rapid solidifying

It should be possible to reduce alloy elements compared
to conventional materials*EU equivalent X40CrMoV5-1

Development concept
development
Alloy design that utilizes features of additive manufacturing
S-MECTM40D: Improve thermal conductivity by reducing alloy elements required to ensure hardenability of casted JIS-SKD61
S-MECTM34D: Improve moldability by modifying alloy design from S-MECTM40D to control deformation during additive manufacturing
S-MECTM24M: Improve thermal conductivity by reducing alloy elements required to prevent embrittlement of maraging steel

(Technical introduction)
Technical issues of conventional materials
Die casting is a process of forming metal parts by forcing high-temperature molten aluminum alloy into a mold athigh pressure. Die casting molds have internal water-cooling channels for control of mold surface temperature andmold cooling that are critical to productivity and product quality. Making the molds by additive manufacturing greatly
increases the degree of freedom in design of the water-cooling channels, enabling effective cooling of the moldduring die casting. However, the hot-work tool steel JIS-SKD61 (EU equivalent X40CrMoV5-1) widely used for diecasting molds has a tendency to crack during additive manufacturing. Moreover, maraging steel with excellent
moldability has low thermal conductivity, leading to insufficient mold cooling during die casting. Various
manufacturers have been seeking to develop new alloys that overcome these technical issues. However, since thethermal conductivity and structure of the mold greatly affect the productivity and quality of die cast products, there
has continued to be a need for new materials with high thermal conductivity that also have outstanding 3Dmoldability.

Development concept
In addressing this challenge, Sanyo focused on the processes for rapid melting and solidifying of materials during
additive manufacturing. Various alloy elements have been conventionally added as casting materials to maintainquality, and by optimizing the necessary quantities of such elements for additive manufacturing, we have developed
new alloy powder that achieves both thermal conductivity exceeding the limit levels of conventional materials andexcellent 3D moldability.
Modified JIS-SKD61

S-MECTM40D: As a general rule, the thermal conductivity of steel materials declines when they contain greater
quantities of alloy. However, in JIS-SKD61, widely used in die casting molds, large amounts of hardenabilityenhancing alloying elements are added to achieve the hardness necessary in mold use.
Sanyo noted that it should be possible to reduce the quantity of alloy elements compared to the amount added toJIS-SKD61 as a result of the hardening effectiveness achieved by rapid melting and solidifying in each micro area
during additive manufacturing. While ensuring the hardness necessary for use in molds and 3D moldability, Sanyothen developed new material that achieved the highest level of thermal conductivity among similar materials by
reducing alloy elements that impair thermal conductivity.
Development
concept
Characteristics

Reducing alloy elements that impair thermalconductivity
Highest level of thermal conductivity among similarmaterials: 40W/(m･K)
1.7 times greater than JIS-SKD61

S-MECTM34D: Based on the alloy design of S-MECTM40, moldability wasimproved by controlling the martensitic transformation temperature.
This material has thermal conductivity 1.4 times higher than JIS-SKD61
and enables additive manufacturing of large molds of 180 mm diameter.
Development
concept
Characteristics

Controlling the martensitic transformation
temperature
Enables large molds of 180 mm diameter
Example of mold using S-MECTM34D

Modified maraging steel
S-MECTM24M: Maraging steel is advantageous for increasing the size of additive manufacturing. However, its
thermal conductivity is significantly inferior to JIS-SKD61 because it contains many alloy elements necessary to
prevent embrittlement in aging heat treatment.
Sanyo noted that it should be possible to reduce the quantity of alloy elements compared to the amountcontained in conventional maraging steel by inhibition of embrittlement through rapid solidifying during additive
manufacturing.
By identifying the alloy design that most efficiently heightened thermal conductivity, Sanyo then succeeded indeveloping new material that maintains outstanding mechanical properties and 3D moldability while achieving
thermal conductivity 1.4 times that of conventional maraging steel and equivalent to that of JIS-SKD61.
Moreover, since maraging steel generally contains cobalt, a specified chemical substance, handling of thepowder requires measures to prevent health hazards such as installing dust eliminators, as stipulated in theOrdinance on Prevention of Hazards due to Specified Chemical Substances.
Sanyo has achieved outstanding properties in a material that does not use cobalt.
Development

Reducing alloy elements required to prevent embrittlement ofconcept

maraging steel

Characteristics

Thermal conductivity 1.4 times that of conventional maraging steel

Total support for customers' additive manufacturing development
In addition to gas atomization facilities that can produce high-quality spherical metal powders, Sanyo has two
metal 3D printers and a non-destructive inspection system (X-ray CT scan). Besides the alloy powder mentioned
above, we are actively working to provide total support for our customers' development, along with providing ideal
metal powders for additive manufacturing through the development of alloy composition optimized for additive
manufacturing, establishing manufacturing processes that maximize material properties, and utilizing rapid material
evaluation systems. We will continue to focus our efforts on developing new products in the NOVASHAPE® Series
and new technologies, providing solutions that utilize materials and technology to improve the competitiveness of
our customers.

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