Accession Number:

ADA608592

Title:

Reactivity of Aluminum-Based Mixtures with Early Transition Metals

Descriptive Note:

Final rept. May-Aug 2012

Corporate Author:

ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Report Date:

2014-08-01

Pagination or Media Count:

90.0

Abstract:

Equiatomic powder mixtures of Al and the early transition metals in Groups IV and V i.e., titanium Ti, zirconium Zr, and hafnium Hf and vanadium V, niobium Nb, and tantalum Ta were prepared by high-energy mechanical alloying. Blends were subjected to microscopy and differential thermal analysis to systematically investigate the efficiency of conversion from reactants to products. Each of the aluminum Al-X blends was created by mechanically milling pure elemental powders with 1.5 weight-percent stearic acid to prevent cold welding to the milling vial s internal walls during the blending process. The as-milled powders were analyzed via Scanning Electron Microscopy SEM, Energy Dispersive X-ray Spectroscopy EDS, X-ray Diffraction Analysis XRD, and Differential Scanning Calorimetry DSC to determine the effect of milling time on the total heat released. These analyses were performed prior and after DSC to compare the morphologies of the reactants and products, as well as to identify the bulk phases present in the product as they relate to the equilibrium phase diagram for that particular mixture. The DSC analysis was performed to measure and determine the total energy released from the mixtures while being heated to 1,000 C at 10 Kmin.

Subject Categories:

  • Inorganic Chemistry
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE