Approach to Optimum Layer Structure of Functionally Graded Materials
Minimum interlayer numbers of functionally graded materials (FGMs) are studied based on the empirical analysis of thermal stress due to the differences in the thermal expansion coefficient and temperature T between sintering and room temperatures. It is found the maximum , and the minimum interlayer number necessary to produce a NiCr / Fly ash FGM structure without interface cracking were 4.0×10-6 K-1, 1080 K, 0.043 and 2, respectively. The condition < 0.043 was derived and confirmed to be valid for available FGM systems.
Akira Kawasaki, Akinaga Kumakawa and Masayuki Niino
K. Hasezaki and Y. Noda, "Approach to Optimum Layer Structure of Functionally Graded Materials", Materials Science Forum, Vols. 631-632, pp. 29-34, 2010