Thixomolding on a global scale

SSIM Technologies Pte. Ltd. is the name of a brand-new international joint-venture company established by equity partners Thixotech Inc., a subsidiary of Amptech Corp., a consolidated group of leading-edge molding and moldmaking companies in Calgary, Alberta, and Advanced Materials Technologies (AMT) Pte. Ltd. of Singapore, a member of Singapore Technologies.

SSIM stands for semisolid injection molding. It's a single-step process for high-volume injection molding of high-performance net-shaped parts in magnesium (Mg). SSIM is better is known as Thixomolding, a process licensed from Thixomat Inc. (Ann Arbor, MI).

The Basics

Thixomolding is a process that combines the best of injection molding worlds with diecasting. That's one reason why this international joint venture is a perfect match: it brings together one company that specializes in metal injection molding, AMT, with another, Amptech, whose strengths are in tooling and design engineering for plastics injection molding. Even better, Amptech also has background experience in diecasting. Together, these two companies hope to speed the rapidly growing acceptance of Thixomolding as a viable manufacturing process, while advancing the state of the art.

"We see Thixomolding as a means of growing our business while meeting the modern requirements of manufacturing in Singapore. Magnesium is experiencing growing popularity, but in Singapore, for environmental protection reasons, the use of SF6 related material and, therefore, the melting of Mg is discouraged. In the Thixomolding process, Mg is not melted in a furnace. It is processed in a semisolid state within the barrel of the machine," explains D. Dunstan H. Peiris, director of technology at AMT. "In a number of markets, we saw the beginnings of a migration occurring away from diecast Mg and aluminum (Al) and from engineering thermoplastics to Mg. Mg Thixomolding is at least 10 to 20 percent less expensive in the total manufacturing cost than Mg or Al diecasting. It will command a strong market in the very near future. We feel we can profit from this, and thanks to our expertise in metal injection molding, we also feel we can enhance the Thixomolding production process."

Where the Markets Are

Peiris says major multinationals have already begun designing and specifying Thixomolded parts in a wide variety of markets, including automotive, control instrumentation, video cameras, cameras, and televisions. Appliances, ordnance, electronic packaging, tape drives, and portable telephones are other applications he mentions. Then there are power tools, office machines, sports equipment, optical instruments, valves, medical devices—the list goes on and on. Housings for portable computers are another good market for Thixomolding; one OEM has already commercialized a portable computer with a durable, inherently shielded Mg-Thixomolded housing. An Mg-Thixomolded video camera also is already on the market.

Canada's Amptech, with a combined average annual sales of $50 million (CDN), was involved in Thixomolding right from the start as a strategic partner and licensee of Thixomat Inc. Thixotech Inc., a newer member of Amptech's group of companies, which has just begun commercial production, is described in company literature as "the world's most advanced Thixomolding facility." Ehor Babij, Amptech's president, feels confident he can make this claim because of his company's well-rounded expertise in both manufacturing and design engineering.

Design Flexibility

"Our focus in the beginning was on how to use this technology to design a part. You can design Thixomolded parts with a metal like Mg that you can't design with anything else—thin walls, thick bosses, pins, cored holes. You can't do that in diecasting—you wouldn't even try. We learned that you can make the material flow like plastic into the mold. We understand Thixomolding flow and the interrelationship between flow and processing parameters. We know more in these areas than anyone else," says Babij. His company also has about 40 molds built specifically for thixomolding. Babij says no one else is near that number.

AMT understood Amptech's lead and realized that by teaming with the Canadians it could quickly acquire much more than it could by simply buying a license. Through a joint research venture, Canada's Alberta Research Council had helped Amptech get started in Thixomolding by providing applied research services in unfamiliar areas like metallurgy. A representative from this council, Dave Ghosh, JRV project manager, met Peiris of AMT at a conference they both attended in Malaysia. They talked and AMT became interested in both the process and in partnering with Amptech. Babij says, "At the same time, we were looking for good, qualified partners in other areas of the world, especially those with industrial designers on staff. AMT had both. It also brings us the experience in the marketplace through its dealings with customers over there much more quickly than we could ever have achieved on our own."

AMT also brings its award-winning expertise in metal injection molding to the partnership. Peiris says, "The company designed and manufactured components for the world's first 1.8 disk drive system, for instance." At its 10,000-sq-m plant, it precision molds more than 40,000 small and intricate metal parts per day at yields up to 94 percent with a Cpk at 1.4 and above. It is growing at 20 to 25 percent per year. Average annual sales currently are at $4.8 million. Metal injection molding is a complex, multistep process. "For anyone that does metal injection molding, Thixomolding is not that difficult," Peiris says.

As you can imagine, the new joint venture faces challenges. Babij says end users want to see a real Thixomolding industry develop before committing designs to Thixomolding standards. It will take time to develop more documentation from longer runs to develop such standards (see related story, p. 64). Peiris adds that demand presently is greater than the machinery makers' ability to supply and that he has to "wait in line" for machines. There are already some 17 Thixomolding machines in operation worldwide, mostly in Japan. But both Peiris and Babij are confident their venture will be successful, and not just in Mg Thixomolding. Work has already begun on Al Thixomolding.

"Al acts thixotropically, although you need a more rigorous construction for the barrel and screw," Babij says. "We're looking to do basic R&D. If we do this R&D over the next year, Thixomolding of Al is only two or three years away. The Mg market potential is so significant right now, there's not a lot of incentive to do Al." Peiris intends to pursue "very accelerated" work on Al Thixomolding. He agrees with Babij, but adds that when Thixomolding of Al is developed, "Thixomolding will explode." And because of their progressive partnering, both companies will be ready.