A number of alloys were processed via thermomagnetic processing (TMP) including 242, 355, and Al-8Ce-10Mg alloys. Mechanical property results from cast tensile samples heat treated in ORNL’s 5-inch superconducting magnet system clearly indicate a 10 to 65% increase in yield strength (YS) and 16 to 37% increase in ultimate tensile strength (UTS) over reported conventional heat treatment practice values depending on the alloys system. All of the TMP solution heat treating and aging times employed in this study were for times significantly shorter than those conventionally required by industrial practice to achieve performance exceeded by the TMP alloys. This indicates this technology could achieve significant energy savings when implemented in a production heat treating environment. Microstructural analyses suggest that the high magnetic fields enable faster dissolution of solute during the solution heat treating cycle. Faster dissolution would be manifest as finer and more copious strengthening precipitates after the aging cycle which would explain the increase in YS and UTS without loss of ductility via TMP. This work demonstrated that TMP can be accomplished in field strengths low enough to be competitive with costs typical of those for products that are hot isostatically pressed followed by conventional heat treatment.
This AFS Members Only Webinar will begin at 1 p.m. CT.