Effect of mechanical alloying on impact initiated reaction characteristics of WZrZn alloy

Abstract:

W has high thermal inertia and low adiabatic flame temperature, which makes it difficult to burn in air. To change the combustion characteristics of W, 20 wt.% Zr was introduced into W by mechanical alloying. XRD, SEM and STEM analysis showed that after ball milling for 30 h, the diffraction peak of Zr disappeared completely, and the W(Zr20) super-saturated solid solution powders with single BCC phase were obtained. Subsequently, WZrZn alloys were prepared by hot pressing with Zn powder as binder. The results of quasi-static mechanical properties tests and ballistic gun experiments showed that the compressive strength and energy release characteristics of W(Zr20)-Zn30 alloy prepared by W(Zr20) alloy powder were significantly better than those of W/Zr20-Zn30 alloy prepared by conventional mechanical mixing. Under the impact velocity of 1200?m/s, the reaction overpressure of W(Zr20)-Zn30 alloy reached?0.21 MPa.?In the analysis of reaction products, a large amount of WO3 were found, indicating that the solid solution of Zr induced the combustion reaction of W, which effectively improved the impact initiated reaction characteristics of the WZrZn alloy.

Key words:Energetic structural materials; mechanical alloying; super-saturated solid solution; W-Zr alloy