Toho Titanium Outlines R&D Programs to Boost Manufacturing Tech for Industrial Applications

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Toho Titanium Co. Ltd., a major Japanese producer of titanium sponge and ingots, is carrying out several development programs in its Metallic Titanium business segment to expand the application range of titanium and its alloys: direct thinfoil manufacturing by an electro-deposition; porous titanium sheets made of titanium powders; and titanium alloy parts manufactured with the blended elemental powder metallurgy.

Toho, through a company spokesman, recently outlined these development programs for the International Titanium Association, and provided information for this article.

The first program is a direct thin foil manufacturing by an electro-deposition route, in which the anode raw material such as sponge titanium is once dissolved into the molten salt electrolyte at high temperature in the form of titanium ions and titanium atoms deposit on the cathode in the form of a thin foil. The idea of this method was originally proposed and demonstrated its validity in 1950s by Dr. Tokumoto and others. It does not need melting, rolling and annealing processes which are indispensable in the conventional thin foil manufacturing.

A4 size Ti foil manufactured by electrodeposition route

Cathode Side View

In spite of such an advantage, a number of issues hindered the industrialization until now. Toho started the research and development program in 2016 and has been conducting the study with emphasizing on the separation of the foil from the electrode, which was the biggest obstacles for the commercialization, as well as the improvement of the productivity, and now fulfilling the study as one of the subjects of a Japanese government funding project (NEDO project). For now, Toho has successfully manufactured A4 size pure titanium foils of 0.1mm in thickness having good quality with the experimental device in the laboratory. The foils can be easily separated from the cathode by hand and are highly purified by an effect of electro-refining. The foils are expected to be used for various applications such as corrosion protection films for steel structures and fuel cell parts after the commercialization in around two years.

The second program is high-functioned porous titanium sheets made of titanium powders manufactured with the hydrogenation dehydrogenation process or fine titanium fibers. Porosity, air/fluid permeability, strength and other performances can be flexibly adjusted by controlling the processing parameters. The development program started around 2010 and four products known as WEBTi® series (WEBTi®-K, T, S and F) have been developed so far. The information is available via https://www.toho-titanium.co.jp/ en/products/webtihp.html. The application development has been accelerated since 2016 especially for the applications of filters, special battery parts, and exterior/interior goods. Some have been already used by particular customers although quantity is limited.

Large sized porous Ti Sheet of 0.5 mm in thickness (WEBTi®-T)

In addition, Toho has also developed the manufacturing process of WEBTi®-T sheets of 880 x 420mm size. It is strongly expected that examples of mass employment application will emerge in one or two years in a lot of industrial fields containing new energies, food processing and hygiene systems.

The third program involves titanium alloy parts manufactured with the blended elemental powder metallurgy—the cold isostatic pressing (CIP)-sinter/hot isostatic pressing (HIP) route. The relatively complicated near-net-shape product made of titanium alloys, such as Ti-6Al-4V, Ti-3Al-2.5V, Ti-5Al-1Fe and MMCs (titanium alloy base metal matrix composites), can be efficiently manufactured using low-cost one-time-use, thin-wall resin mold manufactured with an additive manufacturing 3D-printer in place of conventional reusable rubber mold which is generally one of the factors for high manufacturing cost. In this process, pure titanium powders manufactured with the hydrogenation-dehydrogenation process are used just like porous titanium sheets. Titanium powders are blended with alloying element powders and filled into a special resin mold, then compacted with CIP.

Dumbbell-shaped Ti powder compact and half-cut resin mold after CIPping

After removing the resin mold from the compact, the compacts are sintered in vacuum, during which a titanium alloy having desired composition is synthesized. This method is considered to be useful especially for multi-product low-volume manufacturing. The development program started in 2017 and some potential customers are now evaluating the products. Several new applications are expected to emerge during the next two years. Toho Titanium further expects that automotive parts manufacturers have interest in this technology in the near future although it is developed for targeting general industrial fields such as machine parts and tools.

Since all those three development programs are now on the laboratory stage or small-volume production stage, Toho so far has not made major equipment investments, according to a company spokesman. “However, Toho is ready to judge the investment depending on the progress of the market developments and potential customer interests,” he said. “Market developments are initially conducted domestically in Japan. But the target areas are in the world. Toho is ready for cooperating with every company or institute having interests in the technologies. Toho receives interests from all over the world including North America.”

The basic philosophy behind the development is Toho’s strong belief to titanium metal products; an excellent material having high strength, good ductility, lightweight, and excellent corrosion resistance. “Toho wants people all over the world to enjoy its excellent properties, and wants to contribute to the progress of mankind,” the spokesman said. “This deep affection to titanium is a driving force of the developments. Toho is going to play an important role in developments of titanium application as well as manufacturing technologies of titanium.”

According to information posted on its website (www.toho-titanium.co.jp/en/business/timetal.html), Toho’s business lines include the production of titanium sponge ingots. “The high level of our technologies for manufacturing titanium products is well demonstrated by the fact that our products are used as engine components and structural materials designed for light-weight airframes,” the company said. Its titanium materials also are used for the production of components in the automotive industry, marine structures, power plants, construction, medical areas, and other consumer products.

Separately, as part of its global business outreach efforts, Toho Titanium, in 2019, launched sponge production through a joint venture in Saudi Arabia. In August 2018, the joint venture, known as Advanced Metal Industries Cluster and Toho Titanium Metal Co. Ltd., successfully completed its first batch reduction and distillation test at a new plant, located in a the Saudi Arabia industrial park,. According to information on the Toho website, “the plant will be provided a stable supply of titanium tetrachloride, the primary raw material for titanium sponge, from a titanium dioxide plant adjacent to it. It’s expected the new plant will be among the most cost-competitive titanium sponge plant in the world, taking advantage of Toho’s advanced production technology and competitive energy costs in Saudi Arabia.”

Yoshihiro Nishiyama

Yoshihiro Nishiyama is the president and representative director of Toho Titanium, which has its headquarters in Yokohama, Japan. Founded in 1953, Toho Titanium is involved in variety of businesses such as propylene polymerization catalysts, ultra-fine Nickel powders, high purity titanium dioxide, and titanium powders, in addition to titanium business, all of which were derived from the base titanium manufacturing technologies. Toho’s Functional Chemicals segment produces propylene polymerization catalysts, ultra-fine Nickel powder, high-purity titanium oxide, and other products.