Winners of the EPMA’s 2010 Excellence in Powder Metallurgy Awards. The winning entries highlighted the capabilities of powder metallurgy and demonstrated the continuing advancements in the PM industry.
Components Category – Award of Merit
Brake Band Components
These components produced by Schunk Sintermetalltechnik GmbH, Germany, were presented with an ‘Award of Merit’ in the Components Category. The parts are used in manual seat-height adjustment devices in cars (Fig. 1). With a total of five other uniaxial compacted PM components, a set of two brake bands are fitted into each adjustment unit. It is precisely the narrow tolerances of this component, with a thinnest wall thickness of less than 2mm and an outside diameter of 53mm, which pose a big challenge for PM processing technology. Furthermore, high tolerance demands are placed on the evenness of the component, amounting to 0.2mm with the total height of the part being 4mm. The manufacture of several million such components in compliance with the tolerance demands a carefully controlled and fully linked production process.
Components Category – Highly Commended
MIM Planetary-Carrier with Sun Gear
Parmaco Metal Injection Moulding AG, Switzerland, were ‘Highly Commended’ in this category for their MIM planetary-carrier with sun gear (Fig. 2). The company stated that its customer was looking for a method to produce cost efficiently some 12 million high torque Planet-Carriers with Sun Gear for its high volume requirement of planetary gear boxes, with an outer diameter of only 6.2mm. These Planetary-Gear-Boxes are intended to be used in an opening and closing mechanism for cellular phones. The most cost effective manufacturing route for the high production volumes proved to be MicroMIM because instead of assembling 5 parts, MicroMIM can produce the Planet-Carrier with Sun Gear in one part. Cost savings compared to traditional production techniques are in the range of 40% for this new application.
Components Category – Notable Entries
PM Components for Steering Column Adjustment
Also entered in the Components Category and produced by AMES SA, Spain, were five PM parts (Fig. 3) which are assembled in the steering column of passenger cars and are the essential core of the steering wheel adjustment: up-and-down and in-and-out. Because of the ability of PM to generate complicated shapes, the customer can integrate the whole function in five parts, by designing directly with PM. Only a CNC multiplate press is able to generate the desired shape of the needle drive and the mobile rack. Heat treatment is mandatory because wear is prohibited and the parts are sliding between them in dry conditions. The teeth are very precise, in order to reach a smooth movement. Hardness is also critical with an HRC of 35. These components were introduced in 2007 and are produced at a rate of 1,500,000 parts per year.
MIM Stainless Steel Clock Housing with Brushed Surface Effect
Another entry in the Components Category was this stainless steel MIM clock housing developed by OBE Ohnmacht & Baumgärtner GmbH, Germany, and used in a high-end automotive dashboard (Fig. 4). The company states that the reason for using MIM was to achieve perceived high value and a cool touch by replacing the original metalised plastic material. Using Catamold Feedstock 316L and with a weight per component of 13.6g the items are produced in a one cavity mould. A special feature is that the brushed surface effect is already integrated into the tool. This is an example of where MIM components can be economic when produced only in low quantities due the high value of the item.
Materials and Processing Category – Award of Merit
Ancorsteel® 30 HP
In the Materials and Processing Category the EPMA presented the ‘Award of Merit’ to Hoeganaes Corp., USA, for its Ancorsteel® 30 HP. The water-atomised, prealloyed low-alloy steel powder is specifically targeted at high performance applications and has reduced amounts of the expensive alloying elements, such as Ni and Mo (Fig. 5). The new powder is said to be particularly suitable for Quench and tempered PM parts with smaller cross section sizes where it enables similar heat-treated strength and hardness properties to be achieved as in traditional Mo-prealloyed powders.
Materials and Processing Category – Highly Commended
Improved Corrosion Resistant Stainless Steel Alloy – STX2000
Sintex A/S, Denmark, were ‘Highly Commended’ for a recent development project aimed at producing a new sintered stainless steel alloy with more stable microstructure, higher corrosion resistance and reduced amount of alloying elements (Fig. 6). Molybdenum content was reduced from 6.5% to 3.9%. However, further optimisation was needed in the manufacturing processes to maintain a high level of corrosion resistance particularly in the compaction process and more importantly in the sintering process. As a consequence a new sintering furnace with focus on atmosphere and temperature control was designed and developed. The results were outstanding: an accelerated salt spray test of the new alloy has shown significantly better corrosion resistance than the old STX1000.
Materials and Processing Category – Notable Entries
Starmix BOOST powder mix
Another entry in the Materials and Processing Category included Höganäs AB, Sweden, who developed their Starmix BOOST bonded powder mix. A new innovative lubricant and binder system, in combination with a special powder treatment process, results in mixes having much improved performance (Fig. 7).