Neodymium vs. SmCo Magnets used for Hybrid Electric Vehicles

Permanent Magnets Dominate EV

Neodymium vs. SmCo Magnets – Vehicle electrification is a growing market for rare earth magnets. Consumption of rare earth magnets in transportation is estimated to rise from 7,000 tons in 2015 to 17,000 tons in 2020. Government mandates to reduce pollution, as well as high gasoline prices, are driving users to purchase more environmentally friendly vehicles. Permanent magnet machines are currently the leading choice for high performance automotive applications. The rotor’s well-balanced magnetic field and the lower stator current requirement, paired with very strong positional control, result in a higher motor efficiency. Two common choices for electric vehicle applications are neodymium magnets and samarium cobalt magnets, and each has its advantages.

hybrid-electric-vehicles

hybrid-electric-vehicles

SmCo vs. Neo: Which Performs Better?

comparison-neo-magnet-and-smco

comparison-neo-magnet-and-smco

Temperature Considerations

The decision between SmCo and Neo magnets often comes down to temperature. The elevated temperatures of a vehicle drivetrain require magnets that can resist demagnetization. In most cases, this necessitates the use of samarium cobalt magnets. The thermal demagnetization for SmCo magnets is much lower than for traditional neodymium-based magnets. (Consider the reversible temperature coefficient of 0.035%/C° for SmCo versus 0.10 %/C° for neodymium.)

The graph below shows the remnant flux density (Br) versus temperature for different magnet materials and grades. Even though the neodymium magnet has a higher remnant flux density at room temperature, it quickly crosses the SmCo line.

A four pole motor is meant to operate inside a vehicle’s engine bay, which can have an ambient temperature from anywhere between -40°C and 125°C. This can lead to temperatures over 180°C inside the machine. Having to design around this temperature range leads to large performance differences in the magnet properties. In other words, a machine operating at room temperature will have more torque than a machine operating at 180°C for the same amount of input current.

The smaller demagnetization value of samarium cobalt magnets compared to neodymium magnets results in much flatter operating characteristics across a temperature range. Temperature stability leads to stable output performance from a four pole machine.

Temperature                    Neodymium 38EH Magnets                Samarium Cobalt R35E Magnets
Average torque at 20°C                          2.3Nm                                                         2.14Nm
Average torque at 180°C                        1.86Nm                                                        1.99Nm

Cost Considerations

Neodymium iron boron (NdFeB) magnetic material has a high level of dysprosium, an extremely scarce and expensive rare earth element. Samarium cobalt, on the other hand, is more readily available and therefore more cost effective.

Final Decision

Despite its limitations, neodymium magnets offer the highest energy product of any material today and can be found in a wide variety of applications. When deciding whether to use Neo magnets or SmCo magnets, carefully consider the maximum temperature of the application, the required magnetic output at typical use temperature, and the total cost of the system. So HSMAG can supply the affordable price of NEO and SMCO for you, HSMAG is the best your choose. Neodymium vs. SmCo Magnets.

disc mirco magnets

SmCo Disc Mirco Magnets

SmCo Disc Mirco Magnets, SmCo Disk Mrico Magnets, Rare Earth SmCo Micro Precision Magnets, SmCo Miniature Magnets, Minitype Disc Magnets, Minisize Magnets, Mini-sized Magnets SmCo Disc Mirco Magnets Feature: Material: Samarium Cobalt. Surface Treatments: No coated, Nickel coated,Zinc coated, Gold coated,etc. Maximum Operating Temperature: 250℃ The department that deals with the cutting of is equipped to cut […]

micro smco magnets

Micro SmCo Magnets

Micro SmCo Magnets, Tiny Rare Earth SmCo Magnets, SmCo Micro Precision Magnets, Precision Micro SmCo Magnets, Mini Samarium Cobalt Micro Magnets, SmCo Ring and Block Magnets Micro SmCo Magnets – We specialize in thin-walled and slot-opening miniature ring and block magnet through laser incising, drilling and processing SmCo material. Serial products of SmCo ring and block […]

smco-pot-magnets-with-hole-borehole

SmCo Pot Magnets with Hole / Borehole

Samarium-Cobalt magnets in steelpot with borehole / SmCo pot magnets with hole, SmCo Pot Magnets with Cylindrical Borehole, Samarium-Cobalt Cup Magnet w/ Through Hole Mounting SmCo Pot Magnets Feature: *High resistance to demagnetization *High energy (magnetic strength is strong for its size) *Good temperature stability *Expensive material (cobalt is market price sensitive) * Resistance to […]

smco-countersunk-pot-magnets

SmCo Countersunk Pot Magnets

SmCo Countersunk Pot Magnets, Samarium Cobalt Countersunk Pot Magnets, SmCo Pot Magnets with Countersunk Borehole / 90 ° Countersunk (Countersink) Hole SmCo Countersunk Pot Magnets – High power ‘rare earth’ magnet material. Slightly less powerful than neodymium but works up to 200 °C. (Neodymium is usually only usable up to 120°C.) Use where: High power is required from […]

smco-pot-magnet-with-threaded-bush

Flat Pot Magnet Samarium-Cobalt w/ Screwed Bush

Flat Pot Magnet Samarium-Cobalt with Screwed Bush / SmCo Pot Magnet with Female Threaded (Internal Threaded Stud / Boss Mounting / Threaded Bushing), Samarium Cobalt Shallow Pot Threaded, Flachgreifer SmCo Flat Pot Magnet Execution: Excellent resistance to corrosion, shielded system, galvanized / nickle housing, very large holding force even under temperature influence Mounting:    screw Operating temperature:max. […]

External-Threaded-Stud-smco-pot-magnet

SmCo Pot Magnet with Threaded Stem

SmCo Pot Magnet with Threaded Stem, Samarium Cobalt magnet glued to steel cup. SmCo Pot Magnet with Male Threaded / External Threaded Stud / Boss Mounting, Samarium Cobalt Pot magnets with threaded stem SmCo Pot Magnet Feature: 1. Customized dimensions are available. 2. Surface treatment: Zn coated, Ni coated or according to customer’s requirment. 3. Tolerance […]