Wen Tu, Grand Prize Winner - Scientific Merit

The BSE SEM image taken on the XL30 FEG is of a Nickel superalloy surface with sputter-coated Pt grid. The as-extruded alloy was compressed at high temperature (1925F) to 5% true strain using a Instron compression machine. The sample was induction heated while inclosed in a quartz tube with passing argon gas during compression. The SEM image illustrates several scientific principles: 1. The observed offset of the smaller grains surrounding the large grain in the middle indicates that the alloy deforms superplastically during compression. This evidence is important in determining forging and further thermo-mechanical processing of this alloy. 2. The consistency of the Pt grid within the large grain in the middle indicates that the large grain does not deform under compression. This observation is important in re-designing the alloy extrusion process (especially powder particle size of extrusion) 3. The high deformation of grains above and below the large grain indicates that grains surrounding the non-deforming large grain experience higher localized strain than other grains. The proof of local strain gradient is important in predicting failure location and mechanics during alloy use.
Wen Tu, Grand Prize Winner - Scientific Merit
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