Effects of Dy211 Content on Bending Mechanical Properties of Dy123 Bulks at Room Temperature

Three-point bending tests on specimens cut from the Dy123 with X (X = 15, 20 and 25) mol% Dy211 single-grain bulks were carried out at room temperature. The average value of the Young´s modulus increased with increase of the Dy211 content; these averages are 112, 123 and 133 GPa for X = 15, 20 and 25, respectively. The fracture strength also increased; the average values are 62, 78 and 87 MPa, respectively, and the ranges of data scatter became narrow; the Weibull coefficients are 5.1, 8.9 and 15.0, respectively. On the fracture surfaces of some specimens cut from the bottom region of the bulks, the segregated green phase was observed. By excluding these specimens, the Young´s modulus and the fracture strength of the material without pores were estimated to be 168 GPa and 106 MPa, respectively.