'Best practice' in sintering zone boosts quality of metal-injection-molded parts

MURRAY HILL and NEW PROVIDENCE, N.J., Feb. 10, 2015 /PRNewswire/ -- Advances by Linde LLC and Megamet Solid Metals, Inc. (Earth City, MO) show that a Best Practice in the control of the carbon potential in the sintering zone can significantly improve the quality of metal-injection molded (MIM) parts. 

Improvements were achieved with an advanced SINTERFLEX® Atmosphere Control System (ACS) from Linde (see caption), which will be featured in Linde tabletop sessions and a commercial presentation Tuesday afternoon at MIM 2015 in Tampa, FL (February 23-25).  MIM is the International Conference on Metal Injection Molding of Metals, Ceramics and Carbides, sponsored by the Metal Injection Molding Association (MIMA), a trade association of MPIF, and its affiliate APMI International. 

Megamet, using the advance control system from Linde:

• Reduced the standard deviation of carbon content in MIM parts
• Increased the number of parts in specification
• Eliminated rework / decreased rejects due to carbon content
• Increased productivity

"Homogeneity and consistency in the furnace atmosphere are pivotal to the success of MIM manufacturing," said Bruce G. Dionne, who co-chaired MIM 2014. "The highest accuracy carbon control is achieved by regulating the carbon potential at the sintering temperature to the value that will lead to the desired final surface carbon concentration in the sinter body upon cooling. The SINTERFLEX atmosphere supply system maintains the low CO+H₂ concentration atmosphere necessary to stabilize carbon potential," he explained.

Dionne detailed findings on the Best Practice at the 2014 World Congress on Powder Metallurgy and Particulate Materials (PM2014) last June as General Manager of Megamet Solid Metals, Inc. The PM2014 presentation, titled, "An Approach to Carbon Control of Sintering Furnace Atmosphere: Theory and Practice," is published in Part 5 of the Proceedings of the PM2014 World Congress, available for purchase through the Metal Powder Industry Federation (MPIF). The paper also reviews the causes of decarburization and the dynamics of measuring atmosphere carbon potential.

Linde and Megamet first began working together on the sintering atmosphere control system in 2010.  "After the first SINTERFLEX ACS was installed at the Earth City facility, we identified opportunities for improving the control system and conducted follow-up tests," said Grzegorz Moroz, Linde Program Manager, Heat Treatment & Atmospheres. The Linde project team modified the unit and installed the advanced SINTERFLEX system in December 2013.  Megamet and Linde worked together to evaluate the unit's capabilities, tracking a number of parameters to optimize performance.

MIM offers a low-cost alternative to CNC machining, casting and other manufacturing processes, and can produce high-quality parts in volume, as well as for low-volume prototyping.  The ability to produce complex shapes with superior strength and excellent surface finish make it ideal for many parts used in medical devices, electronics, tools and machines, and aerospace and automotive components.

The powder metal process combines the precision shape-forming advantages of plastic-injection molding with the strength and durability of metals.  The final step in MIM is sintering, the high-temperature hardening process that fuses the high-density alloyed powders by applying heat below the melting point in a controlled atmosphere.  By establishing a carbon-neutral atmosphere during sintering, MIM parts avoid decarburization, a frequent problem that prevents the carbon content from being in specification.

Linde, a leading global industrial gases company, provides portfolio solutions for Heat Treatment. In addition to the SINTERFLEX process, these include the CARBOFLEX solution portfolio, HYDROFLEX atmosphere control systems and the CRYOFLEX cryogenic treatment for hardened steel. For more information, contact Linde (www.lindeus.com), 800-755-9277.

About Megamet Solid Metals, Inc.
The custom metal-injection molding operations of Megamet Solid Metals support customers in firearm components, aerospace, medical device manufacturing, orthodontics, locks and security, hand tools, sensors and many other industrial applications.

About Linde LLC in North America
Linde LLC is a member of The Linde Group. In the 2013 financial year, The Linde Group generated revenue of USD 23.1 bn (EUR 16.655 bn), making it the largest gases and engineering company in the world with approximately 63,500 employees working in more than 100 countries worldwide. The strategy of The Linde Group is geared towards long-term profitable growth and focuses on the expansion of its international business with forward-looking products and services. Linde acts responsibly towards its shareholders, business partners, employees, society and the environment – in every one of its business areas, regions and locations across the globe. The company is committed to technologies and products that unite the goals of customer value and sustainable development.

For more information, visit www.lindeus.com

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Logo - http://photos.prnewswire.com/prnh/20130530/NY23246LOGO-b 

SOURCE Linde North America

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