Experimental Study on Boron-Potassium Nitrate Initiated by Shock

Abstract

This paper is concerned with the shock ignition of pyrotechnic-composition, boron ‐potassium nitrate (B‐KNO3) by means of a one-stage gas gun that is used as a shock-loading device. The pressure ‐time curves on the surface of a sample with different projectile velocities are measured by manganin gauges. Other Hugoniot parameters such as shock-wave velocity, particle velocity, and the approximate values of local sound velocity C0 and coefe cient l related to its property for the B ‐KNO3 samples are also determined. It is shown that the critical shock pressure of the sample with its chemical reaction is about 1.52 GPa with a 3.45- ms time delay. I. Introduction P YROTECHNIC compositions are usually ignited by means of heat, friction, and e ame. However, in modern applications, high requirements on the accuracy of ignition delay and the safety and reliability of the composition are the major considerations in the design of pyrotechnic elements. At the same time, insensitive pyrotechnic compositions are developed in some applications, and ignitions by heat and e ame are avoided by designing regulation. Therefore, shock initiations, which are used to evaluate the shock sensitivity of high explosives in the explosive e eld, are also involved in the study of pyrotechnics. Among the earlier research projects on the shock ignition of pyrotechnics was the work by Hardt and Martinson. 1 The method was used to induce foil vapor or explosion to drive the e ying plate to impact the sample. The velocity threshold of shock ignition was the major parameter measured. Later work includes Lee and Schwarz 2 ; they studied the response of titanium subhydride ‐potassium perchlorate TiH‐KClO4 (33/67) to the shock. The pressures on the impact surface were measured. Shefe eld and Schwarz