Science Seminar


Title: Crystallization during welding of bulk metallic glasses

 

Authors:
Martin Dickey1,2, Cody Bowman1,2, Timothy Pickle1,3, Kayode Oyedemi1,4, Anthony Slater5, Nicholas Hutchinson6, and Richard E. Baumer1
 
Author Affiliations:
 
1. LeTourneau University, 2100 S. Mobberly Ave, Longview, TX, 75602, United States
2. Newport News Shipbuilding

3. Colorado School of Mines, 1500 Illinois St., Golden, CO 80401

4. ARCOTEQ, 14100 Westfair E. Drive, Houston, TX 77041

5. Cambridge Vacuum Engineering, 630 Silver Street Unit 6/7. Agawam, MA 01001

6. Eutectix, 8220 W. Harrison Street, Tolleson, AZ 85353

 

Abstract: Bulk metallic glasses (BMGs) possess high yield strength and corrosion resistance and are attractive for structural applications. However, BMGs are presently not widely utilized in structural applications in part due to crystallization and/or cracking induced by fusion welding processes. In this work, an analytical heat flow model for welding is utilized to propose a figure-of-merit for weldability of BMGs based upon material-specific critical heating rates and critical cooling rates necessary to avoid crystallization. Gas tungsten arc and electron beam welding results on Vitreloy 106a [Zr70Cu13Ni9.9Al3.65Nb3.4 (wt%)] are reported for various welding process conditions and compared to predictions of the weldability model. Initial results suggest that welding-induced crystallization cannot be fully explained by critical heating rate and critical cooling rate crystallization mechanisms alone. Alternative proposed mechanisms will be discussed.