Metal Injection Molded (MIM) parts once again shone in the 2014 Metal Powder Industry Federation (MPIF) PM Design Excellence Awards competition. The winners were announced at the PM2014 World Congress, Orlando, USA, May 18-22 and two industry giants, Indo-US MIM Tec Pvt. Ltd and ARCMIM, led the field.
These award winning parts, stated the completion organisers, prove time and again that PM products, whether manufactured by conventional press and sinter PM or via Metal Injection Molding, are a major competitor in the service of end-users who operate in demanding and highly competitive environments.
The MIM industry continues to push the boundaries of complexity, tolerances, and mechanical properties past their already impressive scope, expanding into new applications and extending opportunities within existing applications.
Grand Prize Awards
Indo-US MIM Tec Pvt. Ltd., Bangalore, India, won the Grand Prize in the Automotive – Engine Category for four MIM parts: blank discharge check, stop discharge check valve, valve discharge check, and CRV spring seat. These parts go into a device that controls fuel flow in Gasoline Direct Injection (GDI) pumps made for Stanadyne Corporation.
Three of the parts are made of 440C stainless steel, while the fourth is made of 17-4 PH. The extremely complex geometry of the blank discharge check, with the intercrossing of holes, required tooling with six side cores, three of which move at different timings.
This design was judged by the manufacturer to be perhaps the most complex high-volume part ever made by MIM. The customer achieved cost savings of close to 35%, while the pump performance was improved by modifying the hole geometry to enhance flow dynamics, with the result being a 10%- 20% fuel economy boost.
FloMet LLC, an ARCMIM Company, DeLand, Florida, USA, won the Grand Prize in the Medical/Dental Category for two 5 mm tines – one fixed, one moving – that go into a thermal tissue fusion and dissection system made by its customer ConMed.
The system uses direct thermal energy and pressure to effectively seal, transect, dissect, and coagulate tissue. Fabricated via MIM from 17-4 PH stainless steel, the tines overcame many molding and processing challenges, including the fixed tine’s length and thin-rib requirements, as well as the need for straightness over its entire length for full functionality with mating components.
Highly innovative tooling and advanced thermal processing techniques were employed to produce two components in a final as-assembled condition with only minimal secondary operations being needed. The fabricator’s expertise in maximizing MIM’s advantages was persuasive in having the customer redesign the product to make MIM the preferred manufacturing method.
A three-piece assembly made by FloMet LLC for Shure Incorporated won the Grand Prize in the Electronic/Electrical Components Category. The parts, a nozzle interface, outer nozzle, and metal collar, go into high-end sound-isolating earphones that enable user-customisable frequency responses.
Made via MIM from 316L stainless steel, the components achieved the objective of producing final net-shape parts that not only met the cost demands of the highly competitive professional-audio market but maintained a cosmetically perfect surface so critical in a consumer product with a clear exterior.
MIM was the ideal choice, as alternative fabrication methods, such as die casting or machining, could not have provided the precision needed at a reasonable cost, nor been able to provide the required material performance.
Awards of Distinction
Indo-US MIM Tec Pvt. Ltd., won the Award of Distinction in the Automotive – Chassis Category for this spur gear made for Magna Closures, Canada.
The gear is used in the rear-door assembly of SUVs to enable their opening in the event of loss of automatic control function.
Made via MIM from 4605 low-alloy steel, the part replaced a gear that was machined and had the pin welded on, achieving estimated savings of 30% in the process. This gear is an outstanding example of MIM’s ability to meet close tolerances on concentricity and perpendicularity on a part with such a lengthy gear profile. The manufacturer delivers 720,000 parts annually.
Indo-US MIM Tec Pvt. Ltd., received the Award of Distinction in the Hardware/Appliances Category for three parts, an output shaft, lever and cover, that are assembled into the quick-change mechanism of a Dremel multitool.
The mechanism allows for the swapping of any tool bit within seconds. Made via MIM from 4605 low-alloy steel, the three parts, designed specifically for MIM, are made close to net shape, with only a few secondary operations performed to achieve close tolerances.
The highly complex geometry of the shaft, with three holes intercrossing at 120 degrees, required six side cores per moulding cavity.
Advanced Forming Technology, an ARCMIM Company, Longmont, Colorado, won an Award of Distinction in the Hand Tools/ Recreation Category for a lock hood for a muzzleloading rifle made for its customer Smith and Wesson.
Manufactured via MIM from 4605 low-alloy steel, the hood’s complex geometry presents a challenge for maintaining the large U-shape sufficiently undistorted so that it can be coined into final tolerance. This is accomplished using a unique sintering and staging approach that utilizes an “active” setter made of a feedstock having a similar shrink rate to the hood.
The MIM process allowed the customer to offer the rifle at the desired price point in this competitive market.
Smith Metal Products, Center City, Minnesota, USA, won an Award of Distinction in the Medical/Dental Category for a MIM 17-4 PH stainless steel shaft assembly used in a novel surgical instrument for passing suture through difficult-to-reach tissue.
Unlike most surgical tools, this instrument is single-use so a precise fabrication process had to be developed that could be scaled up to deliver high volumes at low cost.
The process involves molding the 7” shaft in two parts, laser welding them together, and then performing finish machining, ID reaming, heat treating, sand blasting, and passivation to achieve the tightly toleranced dimensions.
This method was four to five times less expensive than Swiss CNC machining would have been.
Indo-US MIM Tec Pvt. Ltd., won a final Award of Distinction in the Medical/Dental Category for a sound tube used in a hearing aid made by its customer Phonak, Germany.
The part’s function is to enhance sound frequency and improve hearing. Manufactured via MIM from 316 stainless steel, the highly complex part achieves all its features in the as-sintered condition, with only glass bead blasting for a better finish performed as a secondary operation.
An original design for MIM, it is estimated the part provides 20% cost savings over competing forming processes. The manufacturer delivers 500,000 parts annually.