Impact of growth velocity on grain structure formation during directional solidification of a refined Al-20 wt.%Cu alloy

Abstract

The paper presents detailed analyses of solidification experiments performed on a refined Al-20wt.%Cu alloy using the SFINX (Solidification Furnace with IN situ X-radiography) laboratory facility. Directional solidifications of a sheet-like sample were carried out in a horizontal configuration, with the main surface of the sample parallel to the ground. The sample was solidified for a wide range of cooling rates to obtain various grain structures, from columnar to elongated and equiaxed. The formation of the grain structure was observed in-situ and in real-time by X-radiography, which allows the dynamic of solidification phenomena to be thoroughly analyzed. Based on the radiographs, quantitative measurements were performed to

Influence of Bonding Temperature on Interfacial Microstructure and Properties of Hypereutectic Al-Si Joints with Cu Interlayer

“…Firstly, conventional Al-Cu eutectic alloys are usually prepared by a casting method, so an obvious temperature gradient will inevitably occur during the solidification process of the liquid Al-Cu melt. 29 This can drive the a-Al-h-Al 2 Cu eutectic to grow in the direction of the temperature gradient, which is conducive to the formation of regular lamellar structures. In contrast, the eutectic structures in the soldering seams of Al-27Si/Al-50Si joints are formed isothermally by dynamical melting and solidification of the Al-Cu-Si system near the bonding interface during PTLPB.…”

In situ investigation of the Columnar-to-Equiaxed Transition during directional solidification of Al–20 wt.%Cu alloys on Earth and in microgravity

“…The XRMON-GF2 facility is a duplicate of the XRMON-GF (Gradient Furnace) facility developed for the MASER-12 sounding rocket experiment [13] in the framework of ESA XRMON project dedicated to the application of X-radiography during microgravity experiments. It is also similar to XRMON-PFF (Parabolic Flight Facility), which was used during parabolic flights experiments [12] and the SFINX (Solidification Furnace with IN Situ X-radiography) laboratory device [29]. A complete description of those facilities has been presented in these papers.…”

“…A quantitative analysis was made to determine the grain size and grain elongation distribution of the equiaxed microstructure. The procedure was described in detail in [22,29] and only the main steps are summarised hereafter.…”

“…The CET was followed by the propagation of an equiaxed front, as described in section 3.2 and in Soltani et al [29]. The equiaxed grain structure was quantitatively characterised by measuring the grain size and the grain elongation factor defined in section 2.5.…”

“…This study provided direct comparison of terrestrial and microgravity alloy solidification. In the subsequent stage of the project, the first in situ study in microgravity of equiaxed solidification in isothermal conditions was performed in the MASER-13 sounding rocket [29] with a refined Al-20wt.%Cu alloy [14]. In the continuation of those investigations, the present work presents the first microgravity experiment dedicated to the in situ observation of the Columnar-to-Equiaxed Transition in a refined Al-20wt.%Cu alloy.…”