کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1658214 1517662 2013 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Performance of thermally sprayed Si/mullite/BSAS environmental barrier coatings exposed to thermal cycling in water vapor environment
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد فناوری نانو (نانو تکنولوژی)
پیش نمایش صفحه اول مقاله
Performance of thermally sprayed Si/mullite/BSAS environmental barrier coatings exposed to thermal cycling in water vapor environment
چکیده انگلیسی

The ongoing development of environmental barrier coatings (EBCs) offers the prospect to implement the full potential of silicon-based ceramic matrix composites (CMCs) for high temperature structural applications, more specifically the hot zones of gas turbine engines. The current state-of-the-art EBC system comprises a Si bond coat, a mullite (Al6Si2O13) interlayer and a barium–strontium aluminosilicate (BSAS) (Ba1 − xSrxAl2Si2O8; 0 < x < 1) crack-resistant and water vapor attack resistant top coat. In this study, fully crystalline air plasma sprayed Si/mullite/BSAS-celsian EBCs were engineered under controlled conditions on SiC substrates. The influence of water vapor corrosion on the structural and mechanical properties of a Si/Mullite/BSAS EBC architecture was assessed by furnace thermal cycle testing (i.e.; 50 and 100 cycles, 2 h/cycles at 1300 °C in water vapor atmosphere). The elastic modulus values of the as-sprayed BSAS top coat (~ 75 ± 6 GPa as determined via indentation) did not exhibit major changes after thermal exposure (~ 78 ± 8 GPa). In addition, the BSAS layer exhibited crack healing at high temperatures, the density of cracks decreasing from 15 cracks/cm in the as-sprayed state to 2 cracks/cm after thermal cycling. These characteristics of the BSAS top coat were related to its glass-ceramic nature, the phase/chemical stabilities of the BSAS-celsian at high temperatures and the engineered deposition conditions at which it was deposited. The overall performance at high-temperature of this functionally graded EBC architecture is discussed and correlated to its microstructural characteristics.


► Fully crystalline Si/mullite/BSAS-celsian EBCs were air plasma sprayed on SiC.
► The EBCs were thermally cycled at 1300 °C in a H2O vapor flow up to 200 h.
► Through-thickness cracking or debonding was not detected after thermal cycling.
► The hardness and elastic modulus values of thermally cycled EBCs were determined.
► The crack healing activity of the BSAS top coat was quantified.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface and Coatings Technology - Volume 216, 15 February 2013, Pages 215–223
نویسندگان
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