<Tr> <Td> Tensile strength (N / mm) </Td> <Td> 75 </Td> <Td> 35 </Td> </Tr> <Tr> <Td> Vickers hardness (HV) </Td> <Td> 550--650 </Td> <Td> 500--650 </Td> </Tr> <Tr> <Td> Electrical resistivity (Ω cm) </Td> <Td> (110--170) × 10 </Td> <Td> 86 × 10 </Td> </Tr> <P> Sintered Nd Fe B tends to be vulnerable to corrosion, especially along grain boundaries of a sintered magnet . This type of corrosion can cause serious deterioration, including crumbling of a magnet into a powder of small magnetic particles, or spalling of a surface layer . </P>

Where does neodymium come from to make the magnets