Measurement of the Density of Ni-Cr Alloy by a Modified Pycnometric Method

摘要

A modified pycnometric method has been developed to obtain the accurate density value of liquid nickel and Ni-Cr alloy in the liquid and solid-liquid coexistence states. The density of liquid nickel decreases linearly with increasing temperature in the range from the melting point to 1873K. The density at the melting point and the volume thermal expansion coefficient of liquid nickel are 791Mg centre dot m~(-3) and 1.87 x 10~(-4) K~(-1), respectively. The density of Ni-Cr alloys in the liquid and solid-liquid coexistence states w as found to decrease linearly with increasing temperature and chromium concentration in the alloy. The temperature coefficient of density of Ni-Cr alloys was found to change at the liquidus temperature. The absolute value of temperature coefficient of density in the solid-liquid coexistence state is larger than that of the liquid alloy.