Q-Switched Laser Sampling of Copper—Zinc Alloys

Abstract

A more detailed knowledge than is presently available of laser beam—target material interactions is required if pulsed lasers are to be used with maximum effectiveness as analytical sampling devices. To this end, the Q-switched laser sampling of copper—zinc alloys has been investigated. Both vapor and liquid metal were produced in the sampling process. Observations of the crater dimensions and appearance showed that ablation of molten metal was the predominant material removal mode. It was demonstrated that the melting step was thermally equilibrated. Vaporization proceeded via a sequence of events wherein the vapor composition was independent of laser parameters, and could be predicted from the liquid—solid equilibrium diagram for the copper—zinc system. The effect of laser sampling on a subsequent chemical analysis is illustrated.