Effects of Annealing and Preheating on the Impact Response of Selected Braze Materials$^{1}$

A series of gas-gun experiments has probed the impact response of six different braze alloys: Nicusil 3, Nicoro + titanium (98/2 wt{\%}), copper + gold (65/35 wt{\%}), copper + gold (50/50 wt{\%}), silver zirconate, and Cusil. Velocity interferometer data acquired during this investigation has been analyzed to reveal details of the time-resolved shock/release and spall behavior of these materials. As-received and annealed samples of each alloy were tested under both ambient (room temperature) and preheated (100$^{\circ}$C) initial conditions. The present data have been evaluated to determine the influences of annealing and preheating on the dynamic yield strength (i.e., Hugoniot Elastic Limit) and spall strength.