Lightweight and Efficient Aluminum
Aluminum is the most commonly used material for motor housing, as it has more suitable performance and more reasonable price due to its good heat dissipation and heat conduction. With a density of about 2.7 g/cm³, its product density is only one-third of that of steel, so for applications where weight is a key consideration, it is an excellent material. In addition, aluminum has thermal conductivity that is around 235 W/mK which enable it to dissipate heat very fast. This trait is most pertinent in motor applications where controlling internal heating is critical to achieving performance results and extending the life span of the motor.
Stainless Steel: Ascetically appealing, rugged, corrosion resistant
Stainless steel is optional for corrosive or high-strength environments. It provides outstanding wear and corrosion resistance, which makes it ideal for marine and industrial motor housings. It is also has enough structural integrity to resist breakage and has an ability to endure high temperatures and a range of environmental elements due to its strong stainless steel construction. But it is heavier and has lower thermal conductivity than aluminum which may be a downside in weight-sensitive applications or high-thermal transfer applications.
Plastics – Flexible Cost-effective Materials
Plastics, especially advanced polymers such as polyamide (PA) and polybutylene terephthalate (PBT), are increasingly popular for motor housing designs. These can possess sufficient insulation properties (not necessarily as good as the plastic kind) and resist some corrosion, but they have the benefit of being considerably lighter. Plastics can also be very flexible in injection molding and can produce relatively complex geometries at a far lower cost and much faster than metal alternatives. The trade off is that plastics tend to have lower thermal conductivity and mechanical strength, which relegates them to lower (relative) duty operational situations.
Innovative And High Performance Composite Materials
As motor housing is increasingly fulfilled with composite materials—like fiberglass and carbon fiber reinforced plastics known for high strength-to-weight ratios and thermal properties. The composites can be designed with the characteristics required for specific applications including improved thermal resistance, or reduced weight without compromising strength. The materials are especially useful for certain applications — for example, motors in aviation and ultra-high-performance electric vehicles — where conventional materials fall short of meeting all of the performance needs.
Economical and robust Cast Iron
Cast iron, which is relatively inexpensive, provides excellent vibration control along with good wear resistance and continues to be a practical motor housing material. The design is particularly well-matched to massive industrial motors, due to the whole thing being a little on the heavy side. Cast iron dampens vibration from heavy machinery, which can increase the lifespan of the motor itself and avoid being destructive to the surroundings as a result. Its weight and need to ensure it is treated or refurbished adequately are the most significant drawbacks.
Further Developments in Motor Housing Materials
For a complete overview of materials in use for the latest motor housing designs that cool via water jackets, read more in Motor Housing with Water Jacket.
Final Insights
Materials for Motor HousingSelection of the right material for motor housing will depend on several factors like environmental conditions, weight constraints, thermal management requirements and budgetary constraints. There are advantages and downsides to each, so make sure to weigh the different circumstances of the motor application carefully when deciding on the ideal material. With new materials and composites being developed all the time, motor housing solutions will only grow more efficient as technology allows a wider range of potential materials.