This study manufactures rare-earth permanent magnet alloy strip whose type is d31.44-aFe65.92-bB1Co0.99Cu0.15Al0.2Nb0.3Xa-b(X=Si,Zr,Ga,Gd,Cr,Mn, Ti,V,W) and alloy strip with the type of Cr Nd31.44Fe65.92-aB1Co0.99Cu0.15 Al0.2Nb0.3Cra(a=0.5, 1.0, 1.5, 2.0, 2.5) by changing its amount of Cr and by using a cooling system with horizontal cooling roll, newly made, to design and manufacture high-performance and high-efficiency rare-earth permanent magnet alloy and does HDDR on the manufactured alloy strip and observes micro structure and investigates magnetic features as a basic research on manufacturing of magnet alloy for improving performance of existing high-performance rare-earth permanent magnet and the summary is as follows.
Firstly, it made magnet alloy with the type of Nd-Fe-B by changing rotational speed of cooling roll to 3～11m/s to investigate the optimal driving condition of horizontal RSP device and it was found that dendrite was gotten in the direction from contact surface to free surface until 3～7m/s but the sample, made in 9～11m/s did not get any dendrite but only got fine equiaxed grain.
Secondly, the alloy strip with the type of Nd31.44-aFe65.92-bB1Co0.99Cu0.15Al0.2Nb0.3Xa+b(X=Si, Zr, Ga, Gd, Cr, Mn, Ti, V, W), made in the study, was done with HDDR(HD:815℃ x50min, DR:815℃x60min) and its magnetic feature was studied and it showed that the value of residual magnetization(Mr) of the alloy strip, replaced with Ga, was the highest, 59.14 emu/g, and the value of coercive force(Hc) of the alloy strip, replaced with Cr, was the highest, 10.44 kOe.
Thirdly, the magnetic alloy strip with the type of Nd31.44Fe65.92-a B1Co0.99Cu0.15 Al0.2Nb0.3Cra was made by changing the amount of Cr to 0.5~2.5 wt% and HDDR(HD:815℃ x50min, DR:815℃x60min) was done and its phase change and magnetic features were studied and it showed that the value of residual magnetization(Mr) was increasing when the added amount of Cr was increasing and the sample with the added amount of 1 wt% showed the highest value of coercive force(Hc), 10.44 kOe, as the value of coercive force increased dramatically, but it was decreased when the added amount was increased more than 1.0wt%.