TY - JOUR
T1 - Effect of doping SiC particles on cracks and pores of Al2O3-ZrO2 eutectic ceramics fabricated by directed laser deposition
AU - Wu, Dongjiang
AU - Lu, Fan
AU - Zhao, Dake
AU - Ma, Guangyi
AU - Li, Chaojiang
AU - Ding, Jun
AU - Niu, Fangyong
N1 - Publisher Copyright:
© Springer Science+Business Media, LLC, part of Springer Nature 2019.
PY - 2019/7
Y1 - 2019/7
N2 - Melt growth Al2O3-ZrO2 eutectic ceramic has excellent high-temperature strength, creep resistance, oxidation resistance and ultra-high-temperature microstructural stability, which is expected to become one of the ideal hightemperature structural materials. Directed laser deposition (DLD) is a new technology for fabrication of melt growth eutectic ceramics, which can rapidly fabricate net-shaped ceramics. Aiming at decreasing crack and pore defects in samples prepared by DLD, different proportions of SiC particles (SiCp) are doped into Al2O3-ZrO2. Results show that SiCp distributes uniformly in Al2O3-ZrO2 eutectic ceramic matrix. Interfacial reaction occurs between SiCp and matrix. Two kinds of white phases rich in C, Si, Zr elements are formed around SiCp, and they are closely bonded with SiCp and matrix. The number and the maximum length of cracks in sample decrease obviously with the addition of SiCp. When the content of SiCp increases from 0 to 25 wt%, the number of cracks decreases 93% and the maximum cracks length decreases 92%. Some energy dissipation mechanisms such as crack pinning, transgranular fracture, crack deflection and bifurcation have remarkable effect on crack suppression. In addition, SiCp plays a significant role in eliminating pores, which reduces the porosity from 11.71 to 0.20%. Doping SiCp can increase the temperature and enhance the convection and disturbance of melt pool. Also, it can provide discharge channels for bubbles in melt pool.
AB - Melt growth Al2O3-ZrO2 eutectic ceramic has excellent high-temperature strength, creep resistance, oxidation resistance and ultra-high-temperature microstructural stability, which is expected to become one of the ideal hightemperature structural materials. Directed laser deposition (DLD) is a new technology for fabrication of melt growth eutectic ceramics, which can rapidly fabricate net-shaped ceramics. Aiming at decreasing crack and pore defects in samples prepared by DLD, different proportions of SiC particles (SiCp) are doped into Al2O3-ZrO2. Results show that SiCp distributes uniformly in Al2O3-ZrO2 eutectic ceramic matrix. Interfacial reaction occurs between SiCp and matrix. Two kinds of white phases rich in C, Si, Zr elements are formed around SiCp, and they are closely bonded with SiCp and matrix. The number and the maximum length of cracks in sample decrease obviously with the addition of SiCp. When the content of SiCp increases from 0 to 25 wt%, the number of cracks decreases 93% and the maximum cracks length decreases 92%. Some energy dissipation mechanisms such as crack pinning, transgranular fracture, crack deflection and bifurcation have remarkable effect on crack suppression. In addition, SiCp plays a significant role in eliminating pores, which reduces the porosity from 11.71 to 0.20%. Doping SiCp can increase the temperature and enhance the convection and disturbance of melt pool. Also, it can provide discharge channels for bubbles in melt pool.
UR - https://www.scopus.com/pages/publications/85064220609
U2 - 10.1007/s10853-019-03555-z
DO - 10.1007/s10853-019-03555-z
M3 - Article
AN - SCOPUS:85064220609
SN - 0022-2461
VL - 54
SP - 9321
EP - 9330
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 13
ER -