Moreover, SmCo5 is more expensive than Sm2Co17. Therefore most people will think SmCo5 magnet has no advantage over Sm2Co17 magnet and then application field for SmCo5 magnet is too limited. However, SmCo5 can be used or needed in several following cases:
1. Fixed version of products: SmCo5 magnet was developed earlier than Sm2Co17 magnets. And the design of some products using SmCo5 magnets was tested and validated especially for the microwave communication, defense and military markets. Moreover it will take long time or cost high to validate the updated design with Sm2Co17 magnets. Difference between SmCo5 and Sm2Co17 is not big. In order to keep the consistency of the product properties, SmCo5 magnet remains in use regardless of advantage of Sm2Co17 magnet.
2. Easy to magnetize: Normally the Hcj ranges 15 to 20 kOe for SmCo5 magnets, while exceeds 20 kOe for Sm2Co17 magnets. It’s easy to magnetize magnets with lower Hcj to saturation. Some customers need SmCo magnets supplied unmagnetized and assembled products to be magnetized by their own magnetizer and magnetizing coil. Most customers are equipped with the magnetizing equipments with lower capacity enough for other widely used magnetic materials, such as Ferrite, Alnico or NdFeB magnets, while too low to magnetize Sm2Co17 magnet to saturation. It’s expensive to buy a new high capacity magnetizing equipment for Sm2Co17 magnets specially. And then SmCo5 magnets are required instead.
3. Easy to machine: SmCo5 has better machinability than Sm2Co17, and easier to produce complicated shape and size required.
Why SmCo5 magnet is more expensive than Sm2Co17? The main reason comes from the composition of raw materials. For Sm2Co17 magnet, the material composition is Sm, Co, Cu, Fe and Zr, and the expensive materials are Co accounting for 50% around and Sm accounting for 25% around. For SmCo5 magnet, the material composition is Sm accounting for 30% around and Co accounting for 70% around, for Pr + Sm accounting for 30% and Co accounting for 70%. Co is a type of strategic metals and expensive.