A Thermodynamic Study of the Liquid Cu–Sn and Cu–Cr Alloys by the Knudsen Cell-Mass Filter Combination

Abstract

A study of the thermodynamics of the liquid alloy systems Cu–Sn and Cu–Cr has been made with the combination of Knudsen cell and quadrupole mass spectrometer. From the data obtained, the activities in the liquid Cu–Sn and Cu–Cr systems, and the heats of mixing in the liquid Cu–Sn system were calculated.
The activities and the heats of mixing for Cu–Sn alloys showed a good agreement with those of other investigators.
The activity of Cr in Cu–Cr alloys showed a large positive deviation from Raoult’s law. The liquidus line of the Cu–Cr system in the Cu-rich concentration range was determined from the break points of the ion current ratios in the mass spectrometric measurements as well as the differential thermal analysis.