| Physical properties were investigated in the NiCrAlY/PSZ composites with various NiCrAlY contents(0vol%, 20vol%. 40vol%. 60vol%, 80vol%, 100vol%). Samples of the NiCrAlY/PSZ composites were sintered in the temperature range of 1450 to 1200℃ by a Plasma Activated Sintering(PAS) process. SEM micrographs revealed that grain size of the PSZ, as a matrix in NiCrAlY/PSZ composites, decreased with increasing NiCrAlY content. Hardness values also decreased with increasing NiCrAlY contents. Sintering temperature was found to decrease with increasing NiCrAlY contents in hardness and density measurements. X-ray analysis revealed that the volume fraction of the tetragonal phases in PSZ, as a matrix in NiCrAlY/PSZ composites, increased gradually with increasing NiCrAlY contents and reached the maximum in the NiCrAlY content of 40vol%, and then decreased remarkably. Optical microscopy showed that the continuous phase in the NiCrAlY/PSZ composites changed from PSZ to NiCrAlY in the NiCrAlY content of 80vol%. On the other hand, fracture toughness values linearly increased with increasing NiCrAlY contents, reached the maximum in the NiCrAlY content. of 60vol%, and then decreased remarkably in the NiCrAlY content of 80vol%. |
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