Impact of Void Structure on Initiation Sensitivity

Abstract

The influence of microstructural variation on the initiation of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) has been evaluated. These evaluations encompass two classes of fine‐grain HMX, Class 5 and Fluid Energy Milled (FEM). Initiation data of HMX using thick Polyimide flyers (203 μm) near the power flux (Πc) limiting condition (2.26 GPa to 4.63 GPa) as a function of density are presented. The initiation results depict decreasing threshold velocities as density decreases for both materials. The Class 5 has a lower threshold velocity value than the FEM at comparable density values. Microstructure evaluations based solely on the total specific interface area (SIA) are inconsistent with the initiation results. Further evaluation resulted in the requirement of calculating cumulative SIA as a function of feature size to match the trends observed in threshold behavior. The results support the concept of an activated hot spot size as a function of pressure as formulated by Khasainov et al. [1]. Analysis of the microstructure indicates the distinguishing features between Class 5 and FEM are the large particle size tails of the distributions.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jan 23, 2020
Source ID
10.1002/prep.201900206

Entities

People

  • Christopher D. Molek
  • D. Barrett Hardin
  • Eric J. Welle
  • Jesus O. Mares Jr.
  • Jim Vitarelli
  • Matthew Stuthers

Organizations

  • Air Force Office of Scientific Research
  • Air Force Research Laboratory
  • University of Dayton

Tags

Readers

  • Powder metallurgy of Titanium alloys.
  • Regression Analysis.
  • Structural Health Monitoring of Composite Structures.