| No. |
additives |
function |
effect |
| 1 |
SiO2 |
Reducing the sintering temperature and the silicate formation of the glass state with Fe is present in the grain boundary and inhibits grain growth. |
Refine grain and improve Hc. |
| 2 |
Al2O3 |
inhibit grain growth by improving the magnetic crystal anisotropy field and increasing the critical size of single domain. |
Raise Hc, but Br will drop. |
| 3 |
Al2O3· SiO2· 2H2O |
In the process of sintering, a thin layer of glass crystal is formed in the grain boundary, which can inhibit the growth of grain. |
Reduce sintering temperature, raise Hc, (BH) Max. |
| 4 |
Bi2O3 |
Reduce melting point, reduce sintering temperature, promote solid phase reaction, increase the shrinkage rate of products. |
Increase the density of the product, raise Br, (BH) Max. |
| 5 |
CaCO3 |
After decomposing, Ca2+ enters the structure of the magnetic lead stone and produces low melting point material in the sintering process to promote the solid reaction. |
Increase the density of the product, raise Br, (BH) Max. |
| 6 |
SrCO3 |
Increase the product’s orientation to increase the density of the product, increase Br, (BH) Max. |
improve Br, (BH) Max. |
| 7 |
B2O3/ H2BO3 |
When sintering, the eutectic temperature can be reduced to form a liquid phase sintering condition. |
Increase the density of the product, raise Br, (BH) Max. |
| 8 |
Pb3O4、 PbO |
PbO 6Fe2O3, which generates low melting point with Fe, produces the opposite reaction during the sintering process. |
Increase the density of the product, raise Br, (BH) Max. |
| 9 |
La2O3 |
Refine grain and homogenize. |
Raise the rectangle ratio, improve Hc, and extend the sintering temperature. |
| 10 |
NaF、SrF BaF、CaF |
Form MO·6Fe2O3, act as catalyst, promote solid opposite. |
Improve the mechanical properties of Br, Hc, (BH) Max and improve product performance.
It can reduce the preheating temperature and improve the pulverizing efficiency. |
| 11 |
MnCO3 |
inhibit the growth of grain and homogenize grain by improving the anisotropy of materials and improving the viability of powder. |
Increase Br, (BH) Max, but overdose can cause Hc to drop. |
