Free Upsetting of Heated Cylindrical Specimens of Powder Materials ASTALOY 85 Mo and DISTALOY HP-1 from HÖGANÄS

Application of ultrasonic testing method for determining defects of hot-deformed powder materials

“…It should be noted that there is very little information in the literature about changes in the elastic characteristics of sintered materials depending on their porosity. Some of them are devoted to theoretical methods for determining the elastic modulus and Poisson's ratio [1], and some − experimental [2,3].…”

“…, 0 -density of quartz sensor and sample; , 0 -quartz sensor and sample lengths; ∆ , ∆ -average frequency differences between neighboring harmonics. The elastic modulus was determined by the relations [1,3,4]…”

“…The results of measurements of the phase velocities of longitudinal and shear ultrasonic waves, as well as calculated by the formulas (1-6) values of Jung's modulus, shear and Poisson's ratio, as well as porosity values in the center (C) and periphery (P) of all studied samples are presented in Table 3. Determination of the bulk porosity R from theoretical calculated and experimentally measured values of longitudinal ultrasonic wave velocities [1,5,6] in the studied areas of the samples gives the values presented in Table 3. * Samples with visually absent defects of the peripheral region were selected for analysis, it was assumed that they are borderline.…”