New Intermetallic Strengthened Cobalt Alloys

Tresa Pollock, University California-Santa Barbara, DMR 1008659

New Co-Al-W base alloys strengthened with intermetallic L12 precipitates have melting temperatures 100˚C – 150˚C higher and strengths in excess of the strongest Ni-base alloys above 900˚C

Quaternary Co-base single crystals containing 2at% Ti exhibit a 30˚C creep benefit compared to a commercial Ni-base single crystal. Abundant superlattice intrinsic stacking fault (SISF) observed in this alloy after 2% creep strain.

Density functional theory (DFT) calculations show that the the Ti addition substantially increases the SISF; other additions that increase SISF being explored for strengthening

RISE (Research Interns in Science & Engineering) Intern, Rachel Traylor from Clemson University joined the Pollock group for a 2011 Summer Research Internship

Pollock Group advised two high school CAMP (California Alliance for Minority Participation) 2011 interns

Alessandro Mottura, a postdoctoral researcher on this program, has just started a position on the faculty at the University of Birmingham

The research results from our program has motivated a large European program (SFB-Transregio with 14 co-PIs); Pollock is on advisory board

New Intermetallic Strengthened Cobalt Alloys

Tresa Pollock, University California-Santa Barbara, DMR 1008659

The graduate student on this program, Mike Titus (above), was awarded a TMS Superalloys Scholarship and is one of a very few students selected to speak at the 12th International Symposium on Superalloys in September 2012