Calling all product designers: Discover what Metal Injection Molding could do for you through these award-winning parts
Metal Injection Moulding is one of the most capable manufacturing processes for small precision components, yet it is also one of the least known. MIM parts are everywhere, from smartphones to watches, cars to aircraft – but these examples are rarely noticed by those outside of the industry. Here, we present the fourteen award-winning MIM parts from the Metal Powder Industries Federation's 2022 Powder Metallurgy Design Excellence Awards. These examples offer an insight into the technology, as well as the opportunity for product designers and engineers to consider how they might use MIM in their own projects. [First published in PIM International Vol. 16 No. 3, September 2022 | 10 minute read | View on Issuu | Download PDF]
A significant number of parts produced by Metal Injection Moulding were amongst the winners in the 2022 Powder Metallurgy Design Excellence Awards competition, sponsored by the Metal Powder Industries Federation (MPIF). These components showcase outstanding examples of MIM’s unique ability to challenge competing technologies. From lightweighting to complex geometries, MIM provides component designers with the ability to utilise advanced engineering methods that add up to part-to-part uniformity for improved product quality; shape and material flexibility; application versatility, and more.
From a product designer or production engineer’s perspective, these award-winning parts offer an opportunity to study how various industries, from consumer goods to aerospace, automotive and medical are leveraging the advantages of MIM. Whatever industry you are in, take the opportunity to see how others are using MIM, and consider how the technology could benefit your business.
Many of MIM’s basic design considerations can be seen throughout, including the choice of injection points, ejector pin positions, the removal of unnecessary material, etc. The various achievable surface finishes are also visible. We hope that these parts inspire you to consider MIM as a production process.
Grand Prize
AUTOMOTIVE CATEGORY:
Kyerim Metal Co., Ltd for Hyundai
A Grand Prize in the Automotive Chassis category for metal injection moulded components was awarded to Korea’s Kyerim Metal Co., Ltd, and customer Hyundai Motor Company, Korea, for a 316L stainless steel rotary wheel used for selecting various internal functions in Hyundai-Kia Automotive Group automobiles (Fig. 1). The MIM part replaced an electroplated plastic rotary wheel and exhibits more than four times the durability of the plastic part.
MIM automotive interior parts, along with parts produced by Ceramic Injection Moulding, are seeing increased use in automotive interiors as manufacturers look to increase the perceived levels of quality in premium vehicles, in particular from an aesthetic and haptic perspective.
AEROSPACE/MILITARY/FIREARMS CATEGORY:
ARC Group Worldwide for Palmetto State Armory
In the Aerospace/Military/Firearms category for MIM components, a Grand Prize was awarded to ARC Group Worldwide, Denver, Colorado, USA, and their customer Palmetto State Armory, Columbia, South Carolina, for a fire control housing that holds the trigger mechanism in a consumer pistol firearm (Fig. 2). The fire control housing mounts into the frame of a pistol and supports various fire control mechanism components. The part facilitates the assembly of the firearm and supports the sear and blocker safety components. MIM is used extensively for the production of sporting and military firearms worldwide, bringing the benefits of the cost-effective, high-volume production of precision components in a wide range of performance materials.
LAWN & GARDEN/OFF-HIGHWAY CATEGORY:
Indo-MIM Pvt Ltd
In the Lawn & Garden/Off-Highway category for MIM components, a Grand Prize was awarded to Indo-MIM Pvt Ltd., Hoskote, India, and San Antonio, Texas, USA, for a rotor flow metre used in an agricultural sprayer made from 17-4 PH stainless steel (Fig. 3). The rotor is used to measure the flow rate of pesticide or fertiliser that passes through an extended boom on either side of a carrier while spraying a field. The rotors were previously machined. MIM processing was more cost-effective than competing processes.
HAND TOOLS/RECREATION CATEGORY:
Indo-MIM Pvt Ltd
Indo-MIM also received a Grand Prize in the Hand Tools/Recreation category for MIM components for a quick-change core retaining anti-drill part used in a security door lock assembly (Fig. 4). The complex part requires high strength and good wear resistance and is made from M2 tool steel. The cube-like structure has four square through-holes and, across its centre, three cylindrical projections, one at each edge and one in the centre. The lock industry is a major market for MIM, thanks to its ability to deliver high volumes of net shape components, eliminating the need to post-process components that are often made of hard to machine materials.
MEDICAL/DENTAL CATEGORY:
Indo-MIM Pvt Ltd
In the Medical/Dental Category for MIM components, a Grand Prize was also awarded to Indo-MIM for a stainless steel curved jaw, part of an advanced bipolar device designed for use in open or laparoscopic tissue sealing surgical procedures (Fig. 5).
For decades, the MIM industry has been relied upon to produce many millions of high-precision single-use surgical instruments in stainless steel. The use of single-use surgical instruments is now commonplace, reducing the risk of infection, and MIM’s ability to cost-effectively deliver extremely small, complex components and assemblies revolutionised the surgical device industry.
ELECTRONIC/ELECTRICAL COMPONENTS CATEGORY:
ARC Group Worldwide
In the Electronic/Electrical Components Category for MIM components, a Grand Prize was awarded to ARC Group Worldwide for a stator assembly (plate and frame) used in small aerospace servo valves (Fig. 6). Both parts are produced using two-cavity, three-plate injection moulds. The stator assembly is part of a flux-carrying device that delivers magnet and coil flux to an armature. The assembly is used in servo valves for flight control actuation. MIM technology offered an opportunity to produce this assembly at a significantly reduced cost. MIM components have been used in the aerospace industry for decades, with applications areas ranging from seat-buckle components to superalloy stator vanes.
Awards of Distinction
AUTOMOTIVE—ENGINE CATEGORY:
Indo-MIM Pvt Ltd
In the Automotive—Engine Category for MIM components, an Award of Distinction was given to Indo-MIM Pvt Ltd., for a vane lever used as a gas flow controller in the turbocharger of an internal combustion engine (Fig. 7). The MIM part is made using HK30 austenitic stainless steel that has good oxidation resistance and strength at operating temperatures of 800–850°C. The part was previously made by machining wrought bar stock. MIM’s ability to manufacture high volumes of hard to machine components to net shape has seen it achieve considerable success in the automotive turbocharger market.
AUTOMOTIVE—CHASSIS CATEGORY
Indo-MIM Pvt Ltd
In the Automotive—Chassis Category for MIM components, an Award of Distinction was given to Indo-MIM Pvt Ltd., for an upper cap, lower cap, split centre, and split centre bleed for a high-end automotive suspension system sub-assembly (Fig. 8). The parts are made from MIM-4605 and heat treated. MIM technology offers an advantage over other production processes in being able to deliver significantly increased shape complexity for suspension system components whilst remaining cost effective for high production volumes.
AEROSPACE/MILITARY/FIREARMS CATEGORY:
OptiMIM, a Form Technologies Company
In the Aerospace/Military/Firearms Category for MIM components, an Award of Distinction was given to OptiMIM, a Form Technologies Company, Charlotte, North Carolina, USA, and their customer Savage Arms Inc., Westfield, Massachusetts, USA, for a MIM-4605 bolt end-cap for an SPR Impulse rifle (Fig. 9). The bolt end-cap has a large, open-structure shape with four side holes. It has comparatively thin walls in relation to its size
Advanced Powder Products Inc.
In the Aerospace/Military/Firearms Category for MIM components, an Award of Distinction was given to Advanced Powder Products Inc., Philipsburg, Pennsylvania, USA, for a one-piece slide release for a firearm (Fig. 10). The part is made from an air quenched and tempered S7 tool steel. The part was originally designed for stamping, but the complex geometry was too much of a challenge for this technology.
HAND TOOLS/RECREATION CATEGORY:
ARC Group Worldwide
In the Hand Tools/Recreation Category for MIM components, an Award of Distinction was given to ARC Group Worldwide for a lock-arm button used in a pocket knife (Fig. 11). When depressed, the button fires the blade open or allows the operator to close the cutting tool safely. The part is made from MIM-420 stainless steel and hot isostatically pressed (HIPed) after sintering. The HIP process is typically used to remove final porosity, resulting in an improved as-polished surface finish. MIM is widely used for the production of handheld multi-tools, nail clippers and other household items. Note that with MIM, textures can be produced in the tooling rather than added post-production.
INDUSTRIAL MOTORS/CONTROLS & HYDRAULICS CATEGORY:
Indo-MIM Pvt. Ltd
An Award of Distinction was given to Indo-MIM Pvt. Ltd. in the Industrial Motors/Controls & Hydraulics Category for MIM components produced for a control cone used as a fluid controller in a fuel pump. This is a highly complex part with a cylindrical stepped outer diameter that tapers like a dovetail towards one end. The part was previously machined, and producing the angular hole required difficult high-volume machining. MIM proved to be the most suitable technology for high-volume production.
PTI (Polymer Technologies Inc. and Schindler Elevator Corp
An Award of Distinction in the Industrial Motors/Controls & Hydraulics Category for MIM components was given to PTI (Polymer Technologies Inc.) and its customer Elevator Products Corporation (a division of Schindler Elevator Corp.), for an elevator button assembly that is impervious to solvents and disinfectants (Fig. 13).
These parts solved a problem encountered during the COVID-19 pandemic – elevator button assemblies machined from stainless steel and over-moulded with polycarbonate threaded inserts were being degraded by the various solvents and disinfectants used to sterilise highly touched areas in elevators.
MEDICAL/DENTAL CATEGORY:
ARC Group Worldwide
In the Medical/Dental Category for MIM components, an Award of Distinction was given to ARC Group Worldwide for a MIM 14-4PH impaction handle lever, a single-use-instrument used in knee-replacement surgery (Fig. 14). Tight profiles are maintained in relation to the distal end of the instrument to ensure proper engagement with mating parts. This impaction handle lever represents one of the first single-use instruments converted from plastic to Metal Injection Moulding.
Further information
For further information on designing for Metal Injection Moulding, visit the PIM International website, where all past issues of this magazine are available to download free of charge, as well as a guide to optimising designs for MIM production, featured within our ‘About PIM’ pages.
The Metal Powder Industries Federation (MPIF) website, and that of its Metal Injection Molding Association (MIMA), also include significant resources on MIM, including past award winners from this competition and a directory of member part producers.
