Hot deformation flow behavior of powder metallurgy based Al-SiC and Al-Al2O3 composite in a single step and two-step uni-axial compression

Hot deformation behaviour of bimodal sized Al2O3/Al nanocomposites fabricated by spark plasma sintering

“…It may be related to the fact that the fine grains formed by DRX are more near the μ-Al 2 O 3 particles instead of n-Al 2 O 3 that oriented in different directions ([001], [101] and [111]). This observation is consistent with the results reported by Nayak & Date (2019). Figure 11 depicts the pole figures of the bimodal sized Al 2 O 3 /Al nanocomposite at the different deformation temperatures for the same strain rate (0.01 s −1 ).…”

“…Since the self -diffusion activation energy of aluminium matrix is 143 kJ mol -1 (Ahamed & Senthilkumar, 2012;Nayak & Date, 2019) and the activation energy is much higher than that of the lattice self -diffusion, this suggests that DRX or DR dominated the deformation mechanism instead of diffusion. On one hand, the n-Al 2 O 3 particles in the aluminium grain interior have a locking impact on the dislocation movement, and subsequently accommodation and increasing the dislocation density vicinity of n-Al 2 O 3 is generated.…”

“…Aluminium matrix strengthening by reinforcing nano‐sized ceramic particles attracts many researchers as it maintains good ductility, high‐temperature creep resistance and fatigue properties (Kang & Chan, 2004; Dash et al ., 2013; Sadeghi et al ., 2017a; Sadeghi et al ., 2020). Equivalent conventional micro‐nanocomposites exhibit significantly lower strength and higher ductility compared to nanostructured materials motivating the need to better understand the microstructural features of the metal matrix nano‐nanocomposite (Ahmadi et al ., 2014; Nayak & Date, 2019). In the past few years, little attention has been paid to the conflict between strength‐ductility of the bimodal sized Al 2 O 3 /Al nanocomposites, especially in their high‐temperature applications.…”

“…(2003) studied the high‐temperature plasticity of a PM Al 2014 alloy and shown that temperature dependent threshold stress is a constant fraction (15%) of the Orowan stress generated by the dispersion of alumina particles and of precipitated intermetallic phases. Very few studies are presented in literature on the constitutive modelling of aluminium alloys matrix nanocomposites produced via SPS and hot formed (Cavaliere et al ., 2019; Nayak & Date, 2019; Sadeghi & Cavaliere, 2019). Here, the recrystallisation behaviour is dependent on the reinforcement dimensions and percentages as well as on the processing parameters (Dingley, 2004; Garay, 2010; Ezatpour et al ., 2015).…”

Hot deformation behavior of the AA6016 matrix composite reinforced with in situ ZrB2 and Al2O3 nanoparticles

“…With the full view of the whole pictures, it can be observed that most curves have an upward trend, this kind of abnormal condition could be attributed to the strain hardening caused by particle strengthening. Nayak et al [21] found that the addition of the particles increased the dislocation density near to the interface of matrix-reinforcement.…”