The effects of W on the crystallization temperature, magnetic property, microhardness and electrical resistivity in a series of the amorphous $Fe_{40}Ni_{42-x}W_xB_{18}$(x=0, 2, 4, 6) alloys have been investigated, and these properties of $Fe_{40}Ni_{38}Mo_4B_{18}$ amorphous alloy were measured to compare with those of W containing alloys.
Amorphous alloys could be fabricated by single roll melt spinning technique in the condition that the surface velocity of copper disk and ejection gas pressure were in the range of 15∼20 m/sec and 4∼7 psig respectively. The crystallizaiton temperature were determined by DTA at a heating rate of 20℃/min. They increased from 408℃ to 458℃ as W contents increased, and the crystallization temperature of $Fe_{40}Ni_{38}Mo_4B_{18}$ alloy was 451℃.
The electrical resistivities were determined by four probe method. They increased from 117μcm to 142μcm as W contents increased, and that of $Fe_{40}Ni_{38}Mo_4B_{18}$ alloy was 146μ$cm. The electrical resistivity measurement at heating rate of 10℃/min represented the same crystallization process as DTA results.
The hardness was measured with Tukon microhardness tester. The DPN increased from 844 to 997 as W contents increased, and the DPN of $Fe_{40}Ni_{38}Mo_4B_{18}$ alloy was 911.
The B-H loop was determined by Hysteresigraph. All the B-H loops showed large jumps and squareness. The residual induction and coercive force (applied field 1 Oe) were obtained in the B-H loop. Residual inductions decreased from 5.59 KG to 3.21 KG, and coercive forces also decreased from 0.1 Oe to 0.05 Oe as W contents increased. $Fe_{40}Ni_{38}Mo_4B_{18}$ alloy had 0.07 Oe and 3.89 KG, respectively.
It was found that all the properties of $Fe_{40}Ni_{38}W_48_{18}$ alloy were comparable to those of $Fe_{40}Ni_{38}Mo_4B_{18}$ alloy.
