The high-temperature thermal expansion of Ni₃Al measured by X-ray diffraction and dilation methods

Abstract

The lattice parameters of Ni3AI have been determined accurately for the temperature range 25 to 594 "C by a high-temperature x-ray powder diffraction method. These data are used to evaluate the coefficients of thermal expansion at various tmperatures. The thermal expansion of Ni3AI has also been measured from 25 to 1000 "C by a dilation method. The thermal expansion values obtained by the dilation method are in good agreement with those determined by the x-ray diffraction method at around room temperature, but the agreement deteriorates with increase in temperature.

Modeling of lattice parameter in the Ni-Al system

“…Both the data by Kamara et al [32] and Stoeckinger and Neumann [45] can be well reproduced by our model (Figures 10(a) and (b), S N ϭ 2.5 ϫ 10 Ϫ3 and 2.7 ϫ 10 Ϫ3 , respectively). On the other hand, Rao et al [52] did not report the composition of their alloy. Their sample was prepared by arc melting and was homogenized at 1273 K and was found to be in the single-phase region by the metallographic method.…”

“…10-Temperature dependence of the ␥Ј lattice parameter (ϩ, [32] M, [45] and L [52] [23] and [36] ) and the model calculation (solid line) (S N ϭ 0.06 pct).…”

“…Using high-temperature X-ray diffractometry, Kamara et al, [32] Rao et al, [52] and Stoeckinger and Neumann [45] investigated the temperature dependencies of the ␥Ј lattice parameter. A typical experimental method includes four steps: sample preparation, heat treatment (homogenization or aging), quenching, and measurement (mostly at room temperature).…”

TEM, HRTEM, electron holography and electron tomography studies of γ′ and γ″ nanoparticles in Inconel 718 superalloy

“…The possible γ and γ orientation relationship is cubeto-cube orientation: {100}γ // {100}γ and <100>γ // <100>γ (Paulonis et al, 1974;Mohan Rao et al, 1989). Between γ and γ phases three equivalent orientation relationships are possible (Sundararaman et al, 1988) Therefore, three zone axes of γ phase correspond to the {100} planes of the γ matrix.…”

Nanoindentation and XRD investigations of single crystalline Ni–Ge brazed nickel-base superalloys PWA 1483 and René N5

“…6). In general, the lattice parameter for the pure element and binary precipitate phases Ni, Ni 3 Al and Ni 3 Ge, which has a value of about 0.3516 nm [18], 0.3571 nm [20] and 0.3567 nm [21], is lower than the values for the ␥-matrix and ␥ -precipitates in typical alloys.…”