Effect of predeformation on microstructure and mechanical properties of Al–Cu–Li–Zr alloy containing Sc

Abstract

The effects of prior cold deformation on the microstructures and the room temperature mechanical properties of an Al-3 . 5Cu-1 . 5Li-0 . 22(SczZr) alloy have been observed by using TEM and tensile test at room temperature. The results show that the alloy has the character of aging hardening, and the major phase of precipitation and strengthening is T 1 phase. The result also show that prior cold deformation leads to more dispersive and uniform distribution of T 1 precipitations. It accelerates aging response, causes earlier aging peak occurrence, and enhances strength greatly. However, the plasticity of the alloy is declined with prior cold deformation. In contrast, excessive prior cold deformation causes coarsening and heterogeneous distribution of T 1 phase. It also reduces the strength of the alloy, therefore, influences the composite properties of the alloy. The favourable prior cold deformation is about 3 . 5% under the experimental condition.

Three-dimensional flow driven by iso- and counter-rotation of a shallow pool and a disk on the free surface

“…Flow transition in melt under the interaction of buoyancy, thermocapillary force and crystal and/or crucible rotation in the Cz configuration have been widely studied by experiments and numerical simulations. The results indicated that the transition from axisymmetric flow to nonaxisymmetric flow is due to the interaction between the horizontal temperature gradient and the Coriolis force ͑known as baroclinic instability͒, 6,11,[32][33][34] or interactions between the vertical temperature gradient and the Coriolis force ͑known as Küpper-Lortz instability͒, 7 or the Marangoni effect ͑known as Marangoni instability͒. [20][21][22] In this study, there is no temperature difference, thus the baroclinic, Küpper-Lortz, and Marangoni instabilities are all unsuitable.…”

Effect of pre-deformation on aging characteristics and mechanical properties of a Mg–Gd–Nd–Zr alloy

“…This was attributed to the heterogeneous precipitation of ␤ 1 (FCC) phase by the authors [10]. Such a thermomechanical processing with predeformation between solution treatment and artificial aging is extensively used in aluminum alloys [11][12][13][14], but rarely in magnesium alloys. Therefore, it should be meaningful to introduce pre-deformation practice into magnesium alloys, especially the newly developed high strength Mg-RE alloys, and perform further study on the structure-property relationships.…”

Effect of cold compression on precipitation and conductivityof an Al–Li–Cu alloy

“…During artificial ageing, these Al–Li–Cu alloys are strengthened by a number of precipitates such as δ′, θ′, T 1 and S′. The artificial ageing response of Al–Li–Cu alloys has been found to be accelerated by plastic deformation prior to ageing owing to the introduction of dislocations (Kumar et al , 1990; Ringer et al ,1995; Liang et al , 2007). Ringer et al .…”