Reaction of liquid aluminium-samarium alloys with B4C at ultra high temperatures
Reactive studies between a packed bed of B4C and Al-Sm-Me (Me = Ti, Zr, Hf) alloy melts were carried out under a pseudo-isopiestic thermodynamic system. A graphite enclosure isolated the system under a temperature gradient with one end reaching temperatures greater than 1800 K and the opposite end of the graphite enclosure contains liquid Al with temperatures approximating 950 K. The liquid Al establishes an oxygen potential to control oxidation of very reactive elements (i.e., Al, Sm and Ti). The Al-Sm-Me alloy infuses into a packed bed of B4C reacting exothermically to form borides and carbides depending on the thermodynamic activities, phase equilibria and temperatures reached. Aluminum was used as a carrier for Sm and Ti, and the key impact is in determining the reactivity of Sm as it penetrates into the pores of the packed bed of B4C. Upon cooling, the boride and carbide may transform into phases depending on the rate of cooling, as well as the stability of the phases. For the Al-Sm/B4C reaction, SmB4 , Al3BC and AlB12 formed as the core compounds though SmC2, Sm2C3 and SmB4 and SmB6 also emerged as minor compounds.
Mechanical engineering|Environmental engineering|Materials science
Shantha-Kumar, Sanjay, "Reaction of liquid aluminium-samarium alloys with B4C at ultra high temperatures" (2015). ETD Collection for University of Texas, El Paso. AAI3708566.