MMC Magazine

Mitsubishi Materials Corporation Central Research Institute Thin Films and Coatings Department conducts research and development on materials and coatings to achieve drastically improved cutting tool performance. In this feature, we report on this highly advanced site and its research and development.

Pioneering research and development with state-of-the-art analysis and evaluation technology

Mitsubishi Materials Corporation Mining Research Institute was established in Shinagawa in 1917 as Japan’s first private research institute. Following relocation to Omiya City (currently Saitama City) in Saitama Prefecture, it embarked on a new path as the Central Research Institute. In 2007, they expanded to Naka City, Ibaraki Prefecture with three branch locations in Omiya, Onahama, and Kitamoto. This year, the institute celebrates its 100th anniversary. The Thin Films and Coatings Department has the largest number of research fellows at the institute. The department focuses on controlling composition, texture, and the interface of hard sintering materials and functional coatings at the nano-level to develop new materials with completely new functions. Department Manager Takatoshi Oshika talked about the strength of the Institute. “We have implemented the most advanced equipment and devices that few other institutes in Japan have and also employ many outstanding researchers with highly-advanced skill levels. The Institute has nine other departments working on a wide range of research themes, including material analysis and electronic materials. These departments are able to quickly apply various technologies in cooperation with one another, which is I believe, a major strength of Mitsubishi Materials. In fact, we have released one new product after another through the integration of technologies developed through different projects. One of these is the world’s thinnest flexible thermistor sensor.”

The Thin Films and Coatings Department has developed elemental technologies that are applied to the manufacture of innovative products such as the UC5105/UC5115 grades. The CVD coating developed for the UC grades has significantly improved service life and increased its wear-resistant by utilising Al₂O₃ coating technology. “Currently, we are researching element technology for PCD drills used in CFRP machining, for which the basic material design has already been completed. We are also researching CVD diamond coating materials for CFRP processing with the hope of applying the technology to the new products in the near future.” He continued, “We are also working on innovative technological development. For example, when we find that the strength of a coating material doubles by making material particles smaller, we need to redesign the device that makes the particles. For our efforts we end up with the only device in the world. Through such development and use of high value-added equipment, I believe we can create innovative materials. It is like a magic ball in a baseball comic. Rather than trying to improve our pitching, we strive to create a magic ball that no one can hit. Innovative product development is our mission.”

Development of CVD diamond coating materials for CFRP machining

Kazutaka Fujiwara joined Mitsubishi Materials 20 years ago and was assigned to the Central Research Institute 10 years ago. He has been in research and development of CVD diamond coating materials for cutting tools for the past five years. Fujiwara said, “Compared with the development divisions at manufacturing plants, this Institute is more remote from our customers. Therefore, I always keep in mind the need to maintain a close working relationship with the development staff at the manufacturing plants because these are the ones that have frequent contact with customers and so best understand their needs. Understanding customer needs, I seek to identify fundamental principles that lead to new hypotheses. The results lead to the drastic improvement of product performance. I am very happy when I hear that products made with the new technology we developed are recognized by the market.” Fujiwara is currently engaged in the research and development of CVD diamond coating materials for CFRP cutting tools used on airframes. “Mitsubishi Materials has already released drills and end mills coated with materials we have developed. We are now working on new coating materials whose performance is even better.”

Striving to develop unique technology that can be applied to the manufacture of new products

In addition to single CFRP, composite materials such as CFRP and aluminium or CFRP and titanium are also used for aircraft parts. Processing different materials with a single tool requires a significant increase in performance. The quality of CVD diamond coating materials required to machine such composite materials is necessarily high. Fujiwara said, “For the processing of CFRP only, the higher the ratio of the diamond is, means the harder the material is, the better the performance of the coating material becomes. On the other hand, if we increase the ratio of diamond to process metals such as aluminium and titanium, the coating materials tend to react to the work materials, which can cause adhesion, lower the precision of the machining and shorten tool life. We need to solve these conflicting problems at the same time, achieve outstanding performance over a wide range of work materials with a single coating material that can significantly elongate tool life while we develop the CVD diamond coating materials.” Fujiwara is working on the development of CVD diamond coating materials that triple tool life when compared with existing materials. Setting the goal of releasing products in FY 2018, everyone on the team is working hard on research and development. “The mission of the Central Research Institute is to create the most advanced technology. We are excited about producing the kind of technologies that only Mitsubishi Materials is capable of so that we can make our customers happy with products they manufacture using our tools.”