Creep and toughness of cryomilled NiAl containing Cr

Abstract

NiAl–AlN + Cr composites were produced by blending cryomilled NiAl powder with approximately 10 vol% Cr flakes. In comparison to the as-consolidated matrices, hot isostatically pressed Cr-modified materials did not demonstrate any significant improvement in toughness. Hot extruded NiAl–AlN + 10.5Cr, however, possessed a toughness twice that determined for the base NiAl–AlN alloy. Measurement of the 1200 to 1400 K plastic flow properties revealed that the strength of the composites was completely controlled by the properties of the NiAl–AlN matrices. This behavior could be successfully modeled by the Rule-of-Mixtures, where load is shed from the weak Cr to the strong matrix.