Over the years, ARC Group Worldwide has had the privilege of working on a wide array of projects, including many that pushed the limits of metal injection molding technology. We’ve been recognized as an industry leader, a company that introduces innovation to expand the capabilities of MIM. Below are some of the patents and awards we’ve received over the years.
Metal Injection Molding Patents
Metal Injection Molded 316L Duplex Stainless Steel
Metal Injection Molded Nickel Free Stainless Steel
Method and composition for making a wire
Method for making molybdenum parts using metal injection molding
Method for bonding powder metallurgical parts
Click on an award below for details:
A Grand Prize in the hardware/Appliance category for MIM Components, has been awarded to ARC Group Worldwide for a gearbox used in a drive system for motorized blinds. The components holds gears that rotate when actuated, to allow blinds function with remote-control device. The part is made using MIM-4605 in a two cavity mold.
Strategic tool design was implemented to allow the 25mm diameter by 63.5mm long core to actuate without causing unintentional damage to the part. Careful timing of slides was required, along with precise draft angles, to permit acceptable part removal from the tool. The greatest challenge is the 41 gear-teethed splines on the entire ID of the part.
An Award of Distinction has been made to ARC Group Worldwide and their customer Cutsforth Inc. in the Electronic/Electrical Components Category for MIM components, for a lower beam EZ change holder for removable brush holders. They are used in brush excitation maintenance on turbine generators in the nuclear, gas, coal, wind, and hydro industries. The parts are over 100mm long and 25mm wide in the sintered state. One of the main challenges was ensuring the sidewalls were perpendicular to the base after sintering. The parts are made to a 7.5 g/cm³ minimum density using MIM-17-4PH stainless steel and have an as-sintered hardness of 27 HRC and a tensile strength of 900 MPa.
An Award of Distinction in the Aerospace/Military/Firearms Category for MIM Components, has been given to ARC Group Worldwide for lever actuators for vanes in a turbo-prop engine. The actuators control the angle of the variable inlet guide vanes and the variable stator vanes. Because of unsupported features, a small bridge was added to maintain the slot geometry, and specialty trays were used through debinding and sintering. Strategic tool design and gate location ensured the bridge was at end-of-fill during part molding. This allowed the removal of potentially unwanted material during the machining process. The parts are made using MIM-17-4PH stainless steel and are Hiped to ensure the specified density of > 7.6 g/cm³ is met.
The Grand Prize in the Medical/Dental Category was awarded to ARC Group Worldwide for a MIM-17-4PH size 5 cutting block made for Smith & Nephew. The block goes into the recently launched Visionaire FastPak Single Use Instruments used in knee-replacement surgery. The extreme complexity created by the overall size of the component, which weighs in at nearly a 3 pound, combined with non-uniform wall thicknesses and the need for stress mitigation for finished machining operations, makes this a highly challenging part to process via MIM. The MIM component is estimated to save 60% in cost over traditional manufacturing methods.
The Grand Prize in the Electronic/Electrical Category went to ARC Group Worldwide for a MIM stainless steel shaft grounding guide section made for Cutsforth, Inc. The guide section is part of the customer's Shaft Grounding System used in brush excitation maintenance on turbine generators in the nuclear, gas, coal, wind, and hydro industries. Although the part design has many undercuts due to the nature of the sliding track features, its design still allows for a two plate mold without any slides. By controlling features such as gate location, fill time, hold pressure, and barrel temperatures, the MIM process was optiimized to produce near final netshape components with great aesthetics.
An Award of Distinction in the Aerospace/Military/Firearms Category was given to ARC Group Worldwide for a MIM low-alloy steel trigger bar made for Honor Defense. The nearly 75mm (3 inches) long pistol part is made up of several complex contours with thin cross-sectional areas, making it impossible to hold distortion free through sintering. Several secondary processes, utilizing a high-resolution multi-view camera system, were optimized to allow micro-adjustment of each contour to meet the profile requirement, while still delivering cost of effectiveness compared with the original machined part.
An Award of Distinction in the Electronic/Electrical Category was given to ARC Group Worldwide for a MIM stainless steel upper beam handle made for Cutsforth, Inc. The part goes into an EASYCHANGE Removable Brush Holder assembly used in turbine generators in 6 the power industry.
Redesigned from a previously 100%-machined part, the as-molded component, with its many intricate details, needs only one slight machining operation to meet tolerance and functional requirements. The re-design to MIM reduced the part cost by 60%.
Another Award of Distinction in teh Aerospace/Military/Firearms Category was earned by ARC Group Worldwide for two MIM stainless steel compensator brakes -a 5.56 and a 7.16 caliber - made for Sig Sauer. The parts are attached to short-barreled rifles to redirect gases and reduce the effects of recoil. Innovative gating and sintering strategies enabled print tolerances to be maintained without secondary sizing or bending operations. In a relatively untapped market for MIM, this new part demonstrates perfectly the sweet spot of complexity, overall size, and cost effectiveness that MIM offers.
The Award was given for a MIM surgical keel punch. The part functions as a broach to remove bone during knee surgery. Made from MIM 17-4PH stainless steel, the part is molded and sintered to net shape with no additional coining, machining, or other post-processing to alter its shape.
The Award was given for a MIM-4140 low allow steel latch. The internal latch drives a subassembly for the telescoping feature of the collapsible stock on MCX and MPX riflles. The part was designed for metal injection molding as it could not be economically made using any other fabrication method.
ARC won the Grand Prize in the Aerospace/Military Category for its metal injection molded 4605 low-alloy steel part. This part is much larger than the typical MIM part and has a complex geometry. The customer previously machined this from bar stock, however ARC MIM was able to save the customer more than 30% of the cost from the legacy process. The front sight base is used on the AR-15 rifle.
The Award was given for a MIM 17-4PH stainless steel ferrule that goes into an aerospace engine made by its customer Rolls Royce. The part provides a conductive path between the screen and the engine, while offering support to single cable and preventing the placement of cable loading on the screen. The component, with its complex geometry, is sintered exactly to net shape, with no secondary operations needed to meet required dimensional specifications. Cost savings were the primary driver for the switch to a MIM part from one machined from bar stock.
ARC won an Award of Distinction in the Medical/Dental Category for a MIM tungsten electrode. The use of tungsten enables the electrode to reach its operating/effective temperature more efficiently and maintain it for a longer time than with other alloys. This electrode is used in a surgical ablation device that uses high temperature for the removal of tissue.
ARC won an Award of Distinction in the Medical/Dental Category for a MIM wedge blank made from 440 stainless steel. The part has a complex and small geometry that pushed the MIM process to the very limits of tolerance capabilities. The part’s 5 mm diameter size, less than half the previous low of 12 mm, enables new procedures to be created and enhances procedures in smaller patients, particularly in the area of pediatrics.
The award was given to a breech block fabricated via MIM from 4605 low-alloy steel. The block is inserted into the slide body of a .22 caliber pistol, creating the breech face and other critical functions. The unique geometry of the part—composed of two large masses separated by a channel running axially down the length of the part, creating two distinct bodies connected by very small ribs—presented a significant challenge to keeping the part together during sintering and maintaining tight final tolerances. The component was manufactured 100% to print with no secondary machining operations; it is heat treated to a hardness range of 37–45 HRC, receives a black oxide finish, and then undergoes a coining operation to qualify the width. Published properties include density of 7.5 g/cm³, ultimate tensile strength of 1,655 MPa, yield strength of 1,480 MPa, and 2% elongation. The fabricator believes this is the first breech block fabricated using MIM, an indication that it is possible to expand the application boundaries for MIM even in a mature arena such as firearms.
The award was given to a three-piece assembly -Nozzle Interface, Outer Nozzle, and Metal Collar- that got into high-end sound-isolating earphones that enable user customizable 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 maintened a cosmetically perfect surface so critical in a consumer product with a clear exterior. The parts have density >7.6 g/cm³, an ultimate tensile strength of 520 MPa, a yield strength of 175 MPa, an elongation of 50%, and an apparent hardness of 67 HRB. 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 required material performance.
The award was given to two 5mm tines -one fixed, one moving- that got into a thermal tissue fusion and dissection system. The system utilizes direct thermal energy and pressure to effectively seal, transect, dissect and coagulate tissue. Fabricated via MIM from 17-4PH 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. The tines have density >7.5 g/cm³, an ultimate tensile strength of 1,190 MPa, a yield strength of 1,090 MPa, an elongation of 6%, and an apparent hardness of 33 HRC. 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.
The award was given to a lock hood for a muzzleloading rifle. Fabricated 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 part has a density of 7.65 g/cm³, an ultimate tensile strength of 1,480 MPa, a yield strength of 1,310 MPa, an elongation <1.0%, and a 48 HRC hardness. The MIM process allowed the customer to offer the rifle at the desired price point in this competitive market.
FloMet, LLC, an ARC Group Worldwide Company, has been awarded the Best Practices in Continuous Improvement Award from the VMA (Value-Added Manufacturing Alliance). VMA is a premier manufacturing alliance located in Florida. The VMA was founded in 1980 by manufacturers and is the voice of over 400 local manufacturers providing information, education and opportunities to help manufacturers grow and succeed. This year marks the 8th Annual Manufacturers Showcase held by the VMA and FloMet, LLC will be awarded the Best Practices in Continuous Improvement Award. This distinguished award is given to the company who has displayed the most successful efforts in continuous improvement and has achieved the greatest results from their manufacturing operations.
The award was given to a 17-4 PH stainless steel jaw used in a Raptor™ grasping device. Made via MIM, the jaws merge into one design the features of both a “rat tooth” jaw and an “alligator” jaw, combining the functions of a grasper and a retrieval forceps that surgeons use to retrieve foreign objects in the body during minimally invasive procedures. The component design is enormously complex due to its small size, thin-wall requirements (0.010 in.), and features required to achieve full functionality with the sharp talons and teeth at net shape. The parts have >7.5 g/cm³ density, 130,000 psi ultimate tensile strength, 106,000 psi yield strength, 6% elongation, and 27 HRB hardness. Only minimal secondary processing—coining to help maintain the alignment of the jaws—was needed, as other geometries and tight tolerances were achieved in the as-molded condition. Alternative processing methods could not have achieved the part’s intricate geometries at a reasonable cost: MIM is estimated to have saved more than 60 percent over die casting or machining the parts.
The award was given to a very complex 17-4 PH stainless steel rotor made by metal injection molding (MIM) and used in a hand-emplaced munitions device. The intricate design is demonstrated by its four holes on two perpendicular planes, two angled slots with square corners, and numerous internal and external radii, flats, slots, and cutouts. All of these features require very tight tolerances: 0.0025 inches to 0.005 inches. Moreover, the square bottom-hole could only be formed by MIM because prior attempts with other fabrication processes, including machining, proved unsuccessful. It is estimated that the machined version of the part could cost as much as five times that of the MIM design. The rotor is made to a density of 7.5 g/cm³ and has an ultimate tensile strength of 75,000 psi, yield strength of 25,000 psi, a six percent elongation, and 27 HRB hardness.
The award was given to a housing cup and lid used in an audio device with magnetic shielding capabilities. This application is the first of its kind in the high-power audio device sector. The anti-magnetic MIM material with high nickel content provides an electromagnetic interference, or EMI, shield, preventing interference from other electronic equipment. While the cup has four thin walls for proper assembly, the new lid design must fit securely into the cup opening; this is to prevent moisture and/or foreign matter from entering the housing, as well as to maintain the EMI shielding capability. Manufactured to 8.30 g/cm³ density, the parts have an ultimate tensile strength of 84,000 psi, yield strength of 32,000 psi, and a 40 percent elongation. Alternative manufacturing processes such as deep drawing, casting, and machining would have required multiple components. Combining these multiple components through the MIM process provided significant cost savings, in addition to eliminating up to 40 percent scrap loss.
The award was given to a safe and arm rotor used in an explosive device made for a Department of Defense application. Produced by the MIM process, the 316L stainless steel part is formed to a density of 7.6 g/cm³. Its significant properties include an ultimate tensile strength of 75,000 psi, yield strength of 25,000 psi, 50 percent elongation, 140 ft.·lb. impact strength and 67 HRB hardness. The complex shape features numerous outside radii and angular surfaces. At least 12 functional features and surfaces are geometrically controlled by concentricity, profile, and true position tolerances. The part is assembled into a housing to provide the two-stage safety for the explosive device. It replaced a zinc die casting whose mechanical properties were ultimately not consistent enough to pass validation testing.
The award was given to a 316L stainless steel compressed-air nozzle. Fabricated via the MIM process, the hollow nozzle consists of top and bottom halves, molded separately, which, after debinding, are sintered together into one piece. The nozzle’s design required that air flow capacity be tightly controlled to ensure optimum use of compressed air, and at the same time complying with U.S. and European Union machine device noise regulations. It can withstand high ambient temperatures and corrosive environments, and meets the hygienic requirements of the food-processing industry. The complex part has a density of more than 7.6 g/cm³, an ultimate tensile strength of 75,000 psi, a yield strength of 25,000 psi, and a 50 percent elongation. After sintering, the seams where the two sections join together are laser welded for a leak-free seal.
The award was given to a hearing aid can receiver made by metal injection molding. The thin-walled part is made from a nickel–iron–molybdenum alloy material that provides the magnetic shunt effect required in the hearing aid to separate the internal receiver signal from the telecoil signal. The previous part which the MIM part replaced was deep drawn and required several interim annealing steps to achieve the necessary depth, as well as to form the internal undercuts. Choosing the MIM manufacturing process provided a 50 percent cost savings over the previous process as well as yielding improved performance.
FloMet, LLC, has been awarded the Best Practices in Award from the VMA (Value-Added Manufacturing Alliance). VMA is a premier manufacturing alliance located in Florida. The VMA was founded in 1980 by manufacturers and is the voice of over 400 local manufacturers providing information, education and opportunities to help manufacturers grow and succeed. This distinguished award is given to the company who has displayed the most successful efforts in continuous improvement and has achieved the greatest results from their manufacturing operations.
The award was given to three parts—bracket, slide, and removable drop-in hook—used in the Damon 3MX self-ligation orthodontic tooth-positioning system. One bracket and one slide go on each tooth with the hook an option for about five percent of the teeth. The very tiny, intricate parts are made by metal injection molding from 17-4 PH stainless steel powder to a density of 7.5 g/cm³. They have impressive physical properties: a tensile strength of 172,000 psi and yield strength of 158,000 psi. All of the parts are made to a net shape. The customer tumble polishes them and performs a brazing operation before assembly.
The award was given to a Damon3 Molar Buccal Tube system used in orthodontic braces. The system consists of multiple parts made from 17-4PH stainless steel. The parts have an ultimate tensile strength of 120,000 psi and a yield strength of 104,000 psi. Elongation is 10% and the heat-treated hardness range is 38–42 HRC. The heat-treated ultimate tensile strength is 185,000 psi and the heat-treated yield strength is 160,000 psi. The tube system was first introduced in the all-metal Damon self-ligating orthodontic appliance. When in full production, this application will total more than 12 million parts annually.
The award was given to an 11-piece automatic biopsy instrument made from a 316L duplex alloy to a minimum density of 7.52 g/cm³. Properties include an ultimate tensile strength of 503 MPa (73,000 psi) and a yield strength of 296 MPa (43,000 psi), a 40% elongation and a HRB hardness range of 70-80. The parts are molded in a single-mold base with five interchangeable modules of two parts each, in addition to a complete mold for the housing the 11 parts, adding only rods, screws and springs. The instrument can be operated easily with one hand, allowing procedures with ultrasound guidance. The product was designed for metal injection molding which is estimated to cost 50% less than machined parts.
The award was given to a disposable unit consisting of scissor blades, a clevis, and an actuator used in endoscopic Metzenbaum surgical scissors. The scissors are used for cutting, cauterizing, and coagulation during minimally invasive cardiac surgery, general surgery, and plastic and reconstructive surgery. Made from 17-4PH material, the parts have a minimal yield strength of 140,000 psi, a minimum ultimate tensile strength of 155,000 psi and a minimum density of 7.5 g/cm³. The blades are molded and sintered flat and then formed to the desired curvature by the customer using a toggle press. The actuator and clevis require a single coining operation to set leg width. The blades are curved in pairs and sharpened by the customer. Both threads on the clevis are molded. Metal injection molding replaced parts previously machined from 303 stainless steel.
The award was given to "pivotal" laparoscopic surgical scissors with cauterizing capability consisting of a helical gear and two separate scissor blades. Made from 17-4PH stainless steel, the parts have a density of 7.5 g/cm³. The small 20-tooth helical gear is produced via an unusual "floating cavity" mold allowing standard ejection of helical parts. The blades are made flat and coined as pairs in a single strike, thus producing mating blades with correct pre-load, relief angle and curvature. The blades are heat treated and aged; blade sharpening is done by the customer. Metal injection molding provided a cost savings of more than 80% compared to machining the helical gear.
The award was given to a complicated clevis used in a sub assembly in an auto steering system. The complex nickel-steel part is made to a minimum density of 7.5 g/cm³. It has a typical ultimate tensile strength of 240,000 psi and a yield strength of 210,000 psi. the design features two different pockets, two through-holes, three multi-axis arms, and clearance pads for mating parts. The D-hole is sized and the part is case hardened MIM technology allowed the reduction in the number of parts in the assembly and provided a 25% cost savings over an alternative process such an investment casting.