Abstract
In this study the effect of cold rolling and homogenization on the transformation temperature, magnetization, magnetostriction and shape memory effect for melt-spun FePd29.5In0.5 and FePd30-xAux (x = 1, 5 and 7) alloys were investigated. The homogenized FePd29.5In0.5 ribbon exhibited complete bct phase while only little bct was observed in the as-spin ribbon, on the other hand, no bct phase was observed in both as-spun and homogenized FePd30-xAux ribbons (x = 1, 5 and 7). The Ms of homogenized FePd30-xAux was found to decrease with Au content, while the Af of as-spun FePd30-xAux increased with Au content. At room temperature FePd23Au7 exhibited complete parent phase. As-spun FePd29.5In0.5 ribbon exhibited higher room temperature saturated magnetization than that of homogenized sample, while the coercive field of the latter is lower. For as-spun and homogenized FePd30-xAux ribbon the room temperature saturated magnetization decreased with increased Au content. The magnetostriction of as-spun FePd29.5In0.5 reached maximum at 375 ppm under 9 kOe at 80° with respect to the field, and that of homogenized sample reached maximum at 415 ppm at 70° under 9 kOe. Homogenized FePd30-xAux exhibited higher magnetostriction under 9 KOe field, and the values are 1240 ppm at 90°, 1330 ppm at 80° and 760 ppm at 90° for X = 1, 5 and 7 respectively. As-spun FePd29.5In0.5 exhibited Two-way shape memory effect with recovery ratio up to 35% after 50 thermal cycles, while the homogenized ribbon showed no shape memory effect due to the BCT phase. For homogenized FePd30-xAux the recovery ratio was only up to 10% after 50 thermal cycles while that of as-spun ribbon exhibited much higher recovery ratio up to 58% for X=7.