Young\u27s Modulus of Single Crystals of Palladium at High Temperatures

Rod-form single crystals of palladium 10～11cm in length were prepared and the thermal expansion and the Young\u27s modulus were measured in the temperature range 0°～600℃ with a dilatometer and by means of a vibrator-controlled oscillator system, respectively. From the measured values, the Young\u27s moduli in the three principal directions of the single crystal were calculated. From the results it has been known that the Young\u27s moduli at 20℃ are 7.35×10^5kg/ cm^2, 13.77×10^5kg/cm^2 and 19.44×10^5kg/cm^2 in the , and directions of the single crystal, respectively. The Young\u27s moduli in the and directions of the single crystal decrease with increasing temperature, while the Young\u27s modulus in the direction increases to a maximum at about 250℃ and then gradually decreases. The Young\u27s modulus for a polycrystal was calculated and the calculated value agrees fairly well with the measured value in the polycrystalline specimen prepared by melting