TECHNICAL PAPER PRESENTATION Thursday November 14 : Annex Hall F203~206 : Auditing charge
Session Chairperson
HIHARA P.E.Office, Dr. Masahiko Hihara

JD24-01

High toughness steels for gigantic diesand molds of die-casting
Daido Steel Co., Ltd.
● Masamichi Kawano, Tetsuya Masuda,		 Nobuyuki Gomi, Takayuki Inoguchi

The integral casting to make car bodies is one of the trends ofdiecasting. The gigantic dies have higher risk of gross cracking
due to low toughness at core. The low toughness comes fromcoarse primary carbides and coarse microstructure. The coarse
carbide is made by small solidification rate of a large ingot. Inaddition, small quenching rate of a large die leads to coarse
microstructure given by transformation at higher temperature.
The new grades exert higher toughness in a large die aredeveloped. In this paper, the behavior of toughness to quenchingrate is mainly shown. And various properties of developed
grades compared with conventional grades are shown.
JD24-02

Characterization of high-performancecoatings for die-casting molds
Kawata PE Office● Dr. Kazuki Kawata
Castec Inc.		 Noriyuki Inatsu, Takasumi Tatsuno,		 Raiichiro Iijima

Aluminum die-casting molds necessitate surface treatmentthat satisfies all requirements for soldering, erosion, andheat-checking resistances. This study explores the feasibilityof fulfilling these requirements by combining an AlCrTiSiN
composite multilayer coating with a nitriding treatment known
for its exceptional toughness. The performance of this combinedtreatment was compared and assessed against gas-nitrided
and other ceramic-coated specimens. To this end, evaluations
performed include aluminum soldering tests using moldrelease agents, corrosion-resistance tests in molten aluminumalloys, room-temperature and high-temperature friction andwear tests, micro slurry-jet erosion tests, and heat-checking
tests. Furthermore, this paper presents the practical results ofapplying the AlCrTiSiN composite multilayer coating to actual
aluminum die-casting molds.
JD24-03

Water cooling effectiveness of Ti matrix
composite shot sleeve and development
for improvement
TYK CORPORATION● Sadayoshi Takayama, Shinji Kajita,		 Yukie Kaku, Masamitsu Takai, Akihiro Kato

Our Ti matrix composite shot sleeve features excellent heatretention property. The sleeve contributes to improved quality
and yield in aluminum alloy die casting by reducing cold flakes.
The most important issues regarding the life of the sleeve arethermal deformation near the pouring port and damage at theimpact area of hot metal. This results in erratic operation of
the plunger tip, unstable injection speed, roughness of theinternal surface of the sleeve, and enlargement of the inner
19 Japan Die Casting Congress

diameter, resulting in replacement of the sleeve. Currently, asa countermeasure for these problems, water cooling is applied
to the impact area of hot metal from behind to achieve a certaineffect.
This time, based on the results of further experiments on thiswater-cooled structure, we present the direction for better
water-cooling conditions.
JD24-04

Investigation of CO2 reduction effects byutilizing surface treatment technology toimprove castability of thin and large diecastings
MEC INTERNATIONAL CO., Ltd.
● Katsuhiro Takami,		 Tetsushi Yamaguchi,		 Shigeki Tamura, Hiroki Osawa

Recently, from the global environment point of view, regarding
die-casting, new function requirement to the product isincreasing. Especially for the electric car parts, from thecircumstance of the rapidly increasement to the requirementof electrification, the study of further weight savings andthinning product has begun. Conventionally, higher speed,
higher pressure and higher temperature are to respondthese requirements. We overcame these issues by using ourtechnology for mold surface treatment to anti-molten metal
repulsion properties. We also confirmed the CO2 reduction
effected by mold life extension, and lower the control of molten
metal temperature.
Session Chairperson
SSK DCTech Hideto Sasaki

JD24-05

Residual stress on inner surface of thebent hole in die-casting die material
SINTOKOGIO, LTD.
● Dr. Eng. Yuji Kobayashi,		 Shuichi Kamori, Yuta Kimura
University of Fukui 		 Professor, Masato Okada, Dr. Eng.

Shot peening is expected to improve fatigue strength by work
hardening and compressive residual stress induced by plastic
deformation when the fine metal particles are impacted on themetal surface. Shot peening is used to prevent stress corrosion
cracking in water-cooled holes of die-casting dies. The diameterof the water-cooling hole is a long, narrow, stop hole, but it is astraight line, so it could be peened.
In recent years, die casting dies have been developed using
metal additive manufacturing technology. There are highexpectations for the possibility of fabricating even complex
design surfaces freely with additive manufacturing. Anotheradvantage is that water cooling holes inside the die can be
designed in any shape, including curved holes.
The surface after metal additive manufacturing generates
tensile residual stress and poor surface roughness. The sameis observed on the surface of the water-cooling holes inside thedie. Residual stress can be removed by heat treatment, but thesurface roughness must be improved.
In this study, we report the results of the new processing
method developed for the surface modification on bent holes indie-casting die materials.

JD24-06

Prevention of corrosion on the innersurface of 3D cooling channel of additive
manufacturing die by electroless Ni
plating
HIBINO INDUSTRY Co., Ltd. ● Makoto Katou, Masahiro Sugiyama,		 Mitsuhiro Karaki
MAEDA GIKEN Co., Ltd.		 Kiyoshi Utsumi, Morimi Shirai,		 Isao Takahashi
Aichi Center for Industry and Science Technology.		 Dr.Eng.Jiunji Umeda, Hirokazu Katou,		 Dr.Eng. Masaki Katou
Aichi Science & Technology Foundation.		 Dr. Eng. Hiroaki Iwahori

The inner surface of the cooling channel of aluminum diecasting molds is prone to corrosion. Rust and scale on theinner surface of the cooling channels not only reduce coolingefficiency, but also cause mold cracking and water leakage due
to corrosion fatigue fracture. In particular, the optimization andmaintenance of the inner surface of the cooling channels aremore important for laminated molds fabricated by the selective
laser melting method, which have a complex three-dimensionalcooling structure, because the roughness of the inner surfaceof the cooling channels is larger. In this development, in orderto prevent corrosion on the inner surface of cooling channels
in die-casting mold, we focused on the anti-corrosion effect ofelectroless Ni plating. The roughness of the inner surface of thecooling channel and the film formation behavior of electrolessNi plating were investigated, and practical aluminum die-casting
was performed to clarify the effect of electroless Ni plating.

JD24-07

Cooling Performance Improvement for DieCasting Molds using 3D Printer Fabrication
and Future Development
Ryobi Limited		 Takarayama Yasuhiro,● Takao Mitsuharu, Kitamura Mitsuaki,		 Kittaka Teruhiko, Miyake Tatsuya

In recent years, die-casting products are required to be
produced with high quality, with complexity shapes, and at thesame time, cost reduction is also required.
Since 2014, our company began verifying the applicability of3D cooling inserts to the die-casting mold, using metal additive
manufacturing technology with the cooperation of externalcompanies.
After verification of their effectiveness, we installed powder
bed metal 3D printer in 2018 to produce 3D inserts in-house.
Initially, there was trial and error in setup methods, forming
techniques, and functional evaluations of metal powders.
Moreover, mold design had to be carried out without existing
standards or benchmarks.
In this report, we will present case studies regarding the design,
manufacturing, and casting of 3D cooling inserts that ourcompany has been working on. Additionally, we will discuss thefuture development of molds using metal 3D printers.

Japan Die Casting Congress 20