Accession Number:

AD1020948

Title:

Microstructural Effects on the Spall Properties of ECAE-Processed AZ31B Magnesium Alloy

Descriptive Note:

Journal Article - Open Access

Corporate Author:

Army Research Laboratory Aberdeen Proving Ground United Kingdom

Report Date:

2016-10-01

Pagination or Media Count:

14.0

Abstract:

Time-resolved normal plate impact experiments and spall recovery experiments were conducted to study the spall behavior of AZ31B-4E magnesium alloy processed via Equal-Channel Angular Extrusion ECAE. The spall strength and incipient spall damage in the specimens were measured at different shock stresses using 51 mm and 105 mm bore gas guns. The Hugoniot Elastic Limit HEL was measured to be approximately 181 3 MPa. The spall strengths extracted from the free surface velocity profiles of the shocked specimens were found to decrease by 5 for shock stresses ranging from 1.7 GPa to 4.6 GPa. However, this reduction in spall strength may fall within the experimental error. Post-test fractographic examinations of recovered specimens revealed that spall failure originated at micrometer-size intermetallic inclusions and propagated through the material by cavitation events with a very limited growth of voids. It was concluded that the strengthening of AZ31B-4E magnesium alloy by the ECAE-process resulted in adverse effects on its microstructure and spall behavior because of the process-induced cracking of intermetallic inclusions and their weak interface strengths.

Subject Categories:

  • Fabrication Metallurgy
  • Ballistics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE