Sponsor: Office of Naval Research, Department of Defense
The research objective is to develop a HVOF (high velocity oxygen-fuel) thermal spray process such that it can produce nanostructured yttria–stabilized zirconia (YSZ) thermal barrier coating material for turbine blades and other structural components. Under the present program, research activities include the following: (1) using methanol milling to produce yttria-stabilized zirconia feedstock powders capable of being HVOF thermal sprayed; (2) designing an agglomeration technique to produce the proper powder morphology and size for improved thermal spraying; (3) attempting to thermal spray both milled and non-milled YSZ powders for a comparison study of coatings; (4) using the four techniques of cryomilling, degassing, HIPing, and extrusion to produce nanostructured consolidated aluminum samples; (5) using an Instron 8801 servohydraulic tensile testing machine with video extensometer to measure tensile and creep properties of consolidated samples; (6) manufacturing by cryomilling and plasma spraying Al-SiC reinforced coatings for turbine applications; (7) using X-ray diffraction, SEM, and TEM to study microstructure and chemical composition of both reinforced and unreinforced coatings; (8) using the Instron and a Nano-indentor to study hardness, modulus, and adhesion of both types of aluminum coatings.