Powder Metal Conversions
Designing for PM
The case for powdered metal over forged or cast iron and aluminum is straightforward: it provides equal or better strength for a lower price, and with consistent high quality. The process is also a good alternative for strengthening some plastic components, such as gears. New manufacturing technologies are expanding the types of products that powdered metal can produce, but not every part is a candidate for conversion.
Our engineering team is a trusted resource for customers looking for conversion opportunities. We earned that trust not only through our extensive experience, but also because we openly engage customers in the process. When we consider a conversion, our engineers collaborate with the customer to determine whether it is suitable for powdered metal manufacture. If it is, we approach the situation from every angle:
- Material system
- Physical specifications and weight
- Mechanical properties
- Cost savings
- Processing options
- Assembly possibilities
Once we complete an initial assessment, we sit down with the customer to discuss the design advantages and weigh any tradeoffs. After customer approval, we manage all manufacturing aspects, including the process planning, tooling, production, assembly, and testing.
No matter how complex your products are, consult the experts at Keystone for powdered metal conversion opportunities. We might be able to provide you with the same exact parts, only stronger, greener, with higher quality, and for less.
A Stronger Range Sleeve at Improved Cost
Challenge: Our customer wanted a low-cost alternative to their wrought steel (SAE 4023) range sleeve. The solution had to be a drop-in replacement that could withstand high-impact loads on the external (3675 ft-lbs.) and internal (1412 ft-lbs.) splines.
Keystone Solution: Our team selected a material system (MPIF FN-0208-180HT) capable of meeting the load requirements, and recommended changes to the geometry and heat treating process to maximize strength. Through FEA analysis and validation testing, we demonstrated the functional capability of the material system and design.
Results: This award-winning range sleeve introduced a novel application for PM. By net forming the metal part—including the 3 splines—with a density of 7.1 g/cc, we offered the customer a high-strength replacement for 30% less cost. No performance issues have occurred over several years of production, with an annual volume of 300,000 parts.×
A Lighter Planetary Carrier with Improved Stiffness for Higher Loads
Challenge: The customer found their current carrier—already made of powdered metal—insufficient. The part lacked proper stiffness at higher loads, and was too heavy and too expensive. They needed a replacement with equal or better strength that also worked with their existing pinion assembly method.
Keystone Solution: To increase stiffness, we redesigned the contour of the carrier leg to create a larger bond area. Our engineers considered a number of variations to find the most effective geometry.
Results: Our optimized design provided the customer with a drop-in replacement that was 1.5 lbs. lighter and 6% stiffer.×
A Park Gear Ready for the Next Generation
Challenge: A customer realized that their current forged steel park gear would not be suitable for their upcoming product requirements. They needed a stronger, less costly, reliable gear capable of loads up to 2500 ft-lbs.
Keystone Solution: Our FEA analysis pinpointed the high-stress areas and helped us create a plan to strengthen those regions. We chose an ultra-high density material (FN-0208-180HT), along with induction hardening and tempering operations. Using a machined prototype, we carried out extensive field testing to determine the ideal specifications.
Results: At a density of 7.4 g/cc, the medium duty park gear outperformed the original product in every test. By optimizing the design for ultimate strength, we achieved loads far exceeding the future requirements of 2500 ft-lbs.×