The metal shell of motor mainly consists of cast iron, steel plate and aluminium. With the pursuit of aesthetic perception of motor by people, the aluminium shell motor is continuously recognized by the market. We are very clear about the difference between the aluminium shell motor and the cast iron shell motor. We should evaluate the performance, cost, working condition compliance and market acceptance of the motor.
Frame size 80 to 200 have both cast iron and aluminium shells. Frame size 315 have no aluminium shells, mainly because of the relatively poor mechanical strength. However, the two materials have little effect on other performance of the motor. We have basically categorized and shared the differences between the two.
The Difference between Cast Iron and Aluminum Shell
The density of aluminium is relatively small, which can reduce the weight of the whole machine. For small size motors, aluminum shell is preferred on the premise of strength conformity. The overall price of the two motors is basically the same, but the appearance effect of the aluminum shell motor is better.
Cast iron shell is durable, can withstand beating, and has high mechanical strength. Aluminum shell is soft and easy to form scars on the surface.
Iron-shell motors are easy to rust, especially in hot and humid weather, but the corrosion resistance of aluminum-shell motors is poor.
The heat dissipation coefficient of aluminium is much better than that of cast iron.
The Advantage of Aluminum Material
Pure aluminium itself has not high mechanical function, but it has light weight and good casting fluidity, which is incomparable with other metals. Moreover, the aluminium element is more active, and can be combined with other metals to become aluminium alloy. Then it needs to be seen with great attention. Some high-end equipment uses this, such as aircraft and other equipment. In fact, most of the aluminium we see is aluminium alloy.
The characteristics of cast iron are that its manufacturing technology is very mature, the threshold of entry is low, and the cost is low. But its defect is only iron-carbon alloy. Compared with aluminium, cast iron is not easy to bond with other metals, which is congenitally determined by its own characteristics.
Aluminum is an active metal, which forms a dense oxide film about 50 A thick (1 A = 0.1 nanometer) on the surface of aluminium in dry air immediately, so that aluminium will not be further oxidized and water-resistant; however, the powder of aluminium mixed with air is extremely flammable; molten aluminium can correspond strongly with water; aluminium is amphoteric, soluble in strong alkali and soluble in dilute acid. This is a problem that must be considered when choosing aluminium housing.
