Resolution of structural transformation of intermediates in Al–Cu alloys during non-isothermal precipitation

Abstract

Abstract

Characterising precipitate evolution in multi-component cast aluminium alloys using small-angle X-ray scattering

“…The Guinier approximation was used, since it is a well-established analysis method in metallic systems [12,15,17,19,26,27]. The precipitate parameter that can be extracted is called the radius of gyration (Rg).…”

“…AA2000 and 7000 series alloys) with low volume fractions of micron-sized constituent particles (i.e. those formed from Al and the impurity elements Fe and Si) [15][16][17][18][19][20][21][22][23][24][25][26][27]. Work on alloys that form a low volume fraction (~1 vol%) of trialuminide precipitates (dispersoids) has been limited to high purity Al-Zr-Sc alloys with ppm levels of Fe and Si [28,29], but not on casting alloy systems.…”

A Study on the Nanoparticles Evolution in Isothermally Aged Strain Glass of Ti48.7Ni51.3 Shape Memory Alloy by In Situ Small-Angle X-ray Scattering

“…For the model fitting, the IGOR program (WaveMatrics Inc., Lake Oswego, OR, USA) was used to perform the nonlinear least-squares calculation to fit the 1D SAXS profile [45]. The SAXS intensity profile caused by disk-/plate-like nanoprecipitates can be expressed as the form factor of polydisperse disks with a radius R and Schulz distribution of the thickness t [17][18][19]45], as given by Equation 1:…”

“…The I total (Q) can be reduced along the azimuthal average of the whole 2D SAXS pattern through the standard calibration and the background subtraction [19,26]. The I nanoprecipitate (Q) profiles were reduced from the sector cut, the same SAXS data as that in Figure 3.…”

“…The SAXS technique has been demonstrated to be an effective tool for quantitatively determining the shape, orientation and size of a large number of polydispersed nanoparticles in bulk samples of various alloys [17], such as Al-Cu and Al-Mg-Si alloys [18][19][20], Al-Cu-Li alloys [21,22], Al-Zn-Mg alloys [23][24][25][26][27], Al-Li alloys [28], Al-Si-Zr-V-Fe alloys [29], Ti-Ni-Hf alloys [30], Fe-Cr alloys [31], Zr-Pd alloys [32] and Cu-Co alloys [33]. Moreover, several SAXS studies have resolved the different structures of two co-existing plate-like precipitates [34][35][36].…”