Case Study: Rack Pinion and Bushing Assembly

Process: Conventional powder metallurgy
Density: 6.7 g/cm³
Tensile Strength: 75,000 psi
Particle Hardness: 52 HRC min.
Apparent Hardness: 20 HRC min.

End Use and Function

This is an assembly consisting of rack, pinion, and bushing used in a patented pergola louver system that allows the pergola to convert to a water-tight shelter.

Rack, Pinion, and Bushing Assembly
2013 Award of Distinction: Rack, Pinion, and Bushing Assembly

Fabrication

The sinter-hardened steel rack and five-level pinion and the copper steel bushing are pressed to net shape with one cross-drilled hole being the only secondary operation performed. The assembly was designed to be sinter bonded for strength. The parts have a typical density of 6.7 g/cm³, 75,000 psi ultimate tensile strength, 135,000 psi transverse rupture strength, and 20 HRC min. apparent hardness and 52 HRC min. particle hardness.

Results

Because of the large number of assemblies required in each louver system, the PM process gave the customer the only cost-effective option, delivering an estimated 75% savings over the machined alternative.