Yoshiko Yamaguchi
Separation and Purification Field
Innovation Center

Cemented carbide tools are indispensable for cutting and processing metal parts for aircraft and automobiles. The demand for tungsten, the raw material required to make these tools, is increasing along with the growth of the aerospace and EV markets. However, tungsten reserves are limited, and extracting it from ore is not easy. Japan New Metals Co., Ltd., a member of the Mitsubishi Materials Group, contributes to the stable supply of tungsten through its business of recycling used cemented carbide tools.
We are currently pooling the group’s resources to develop a new manufacturing method for recycled tungsten and its subsequent mass production.
Since 2021, I have been involved in R&D to implement this new method at our manufacturing sites. We have achieved success in controlling the rate of chemical reactions that occur during the manufacturing process, which was previously considered challenging. This made it possible to manufacture tungsten more efficiently, paving the way for mass production. This manufacturing method also allows for the production of a variety of products with a single process, enabling us to optimally meet the different needs of each customer.
R&D isn’t always guaranteed to produce the desired results, but when we approach phenomena with our company’s R&D principle of valuing principles and fundamentals, it presents an opportunity to understand unknown principles and fundamentals. While it can be challenging to go back to basic testing each time, there is a great sense of achievement when we find the opti- mal solution.

During my on-site training as a new employee, I often heard the question, “Can that manufacturing method be implemented on-site?” These words have significantly influenced my mind- set as a researcher. When I was conducting basic research at university, the emphasis was on clarifying unknown phenomena and laws rather than whether the results could be practically applied in society. So, it was only when
I started hearing this question that I realized I needed to produce not only advanced research results but also ways of solving problems on the manufacturing floor. In other words, regardless of how socially significant our research results may be, they hold no meaning unless our colleagues in the manufacturing department can utilize them.
Even now, I sometimes find myself troubled by the gap between the pursuit of principles and fundamentals and the demands of the manufacturing floor. During such moments, I ask myself questions like, “Would this be easy to operate on-site?” and “Doesn’t this violate any basic principles?” By considering the implementation on the manufacturing floor and working backwards, I confirm the necessary principles along the way. By achieving a balance between a worksite perspective and principles, I aim to continu- ously generate research outcomes that drive Mitsubishi Materials’ technological capabilities forward.

During my university days, I was researching ways to reduce the impact on people and the environment in the synthesis of organic compounds, so I wanted to work for an environmentally conscious company. However, back in 2019, such companies were still in the minority. That’s why Mitsubishi Materials’ corporate philosophy seemed so fresh to me.
The research I am currently conducting on new tungsten manufacturing methods and their mass production has the potential to promote the growth of various markets and enrich people’s lives. However, it’s not enough for people to be prosperous. As I con- tinue my R&D at Mitsubishi Materials, I always ask myself, “What can I do to help realize a sustainable global envi- ronment?”