The challenge
When durability creates a heat challenge
For brake discs used in exposed environments such as bicycles, motorcycles, boat trailers and marine winches, stainless steel offers a compelling advantage over cast iron. Its corrosion resistance, high strength-to-weight ratio and long-term durability make it well suited to these demanding applications.
But this resilience comes with a challenge: stainless steel conducts heat relatively poorly and expands significantly as temperatures rise. During demanding or repeated braking, heat can therefore build up and spread unevenly across the disc, increasing the risk of thermal distortion, warping, accelerated wear and ultimately brake fade.
Our response
Engineering a stronger, more durable brake disc using composite powders
CSIRO set out to overcome this performance trade-off by combining the strengths of metal and ceramic materials in a form suitable for additive manufacturing. Using the NARA Hybridisation System, the team produced SS410L/B₄C composite powders designed to create components with greater hardness, wear resistance and thermal performance than stainless steel alone.
Through the A*STAR–CSIRO Research-Industry (2+2) Partnership Program, CSIRO worked with Romar Engineering to turn the new powder into a prototype brake disc. Using the Lasertec 65 system, Romar laser-cladded the CSIRO-produced composite powder onto an SS410L substrate, building a 3–4 mm composite layer across the disc. The layered design paired a hard, wear-resistant surface with a tough, ductile substrate, bringing together durability, strength and improved thermal performance in a single component.
The results
Delivering a stronger, more wear-resistant braking surface
Testing confirmed that the composite approach delivered a substantial performance improvement. Both the microhardness and tensile strength of the composite layer were more than double those of the base SS410L alloy, demonstrating how the metal-ceramic combination could produce a stronger and more wear-resistant braking surface.
These enhancements highlight the technology’s potential for braking applications where corrosion resistance, durability and mechanical reliability are critical. More broadly, the prototype shows how tailored metal-ceramic powders and additive manufacturing can be used to engineer components that overcome the limitations of conventional materials.