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2188 |
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Wednesday, May 05, 2010, Moor Room 3:00 PM Properties 3 |
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Influence of pores and cracks morphology on mechanical behavior of thermally sprayed ceramics |
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Radek Musalek* / Institute of Plasma Physics of the Czech Academy of Sciences, Czech Republic Jiri Matejicek / Department of Materials Engineering, Institute of Plasma Physics AS CR, Czech Republic Vaclav Pejchal/ Department of Materials, FNSPE, CTU in Prague, Czech Republic Eduardo Mari/ CTSR, Stony Brook University, USA Alfredo Valarezo/ CTSR, Stony Brook University, USA Sanjay Sampath/ CTSR, Stony Brook University, USA |
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Pores and cracks have significant influence on the structural rigidity and mechanical behavior of the thermally sprayed materials. For some applications dense coatings are needed, while for others (e.g. thermal barriers) some level of porosity is desirable. Recent development in thermal spraying focuses on the tailored design of pores and cracks for specific applications. In this project, ceramic coatings with different level and morphology of pores and cracks were plasma and HVOF sprayed on titanium alloy substrates. Coating microstructures were observed using light and scanning electron microscopy. Mechanical behavior of the prepared coatings was evaluated using four-point bending test in terms of changing coating stiffness with increasing mechanical load both in compression and tension. Significant level of coating non-linearity and hysteresis were observed. Tests carried out for coatings with the same chemical composition but different microstructure proved strong dependency of coatings mechanical properties on pores and cracks morphology. Microstructure features relevant for the applied loading are discussed. |