Phase transformation and precipitation of an Al–Cu alloy during non-isothermal heating studied by in situ small-angle and wide-angle scattering

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

“…The thickness, radius and relative volume fraction of Ti 3 Ni 4 nanoprecipitates can be accurately determined by the quantitative model fitting of the 1D SAXS profile. The validity of model analysis regarding the disk-/plate-like nanoparticles has been demonstrated [18]. 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].…”

“…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 nuclei of new nanoprecipitates form with random orientations at new sites, directly resolved by the 2D SAXS pattern. Note that the thicknesses of Ti 3 Ni 4 nanoprecipitate nuclei are much larger than that of the Guinier-Preston zone (GPZ) in the Al-Cu system [18] or Ni-rich nanodomains in the as-quenched Ti 48.7 Ni 51.3 SMA [15]. It is speculated that the quick formation of large Ti 3 Ni 4 nuclei can be attributed to the short-range diffusion of Ni atoms near the sites of concurrently-dissolving Ni-rich nanodomains, or the nucleation site based on the splitting pieces from the original Ni-rich nanodomains, as discussed in Section 4.1.2.…”

“…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].…”

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

“…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.…”