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The metal-matrix composites (MMCs) with biomimetic bricks-and-mortar architectures have been experimentally demonstrated to exhibit excellent strength-ductility match. Here, biomimetic bricks-and-mortar architecture mimicking masonry bonds was introduced in numerical models. By translating perpendicular layers on stack bond model, 1/2 running and running bond models were established. The results reveal that elongation of running bond model is the highest (4.77%), which is ∼ 1.5 times as that of stack type model. The strength of these models is similar (330 ± 1 MPa). However, it is the trade-off between load bearing capacity and fracture of SiC particles. In the stack bond model, over a small junction layer area led to a relatively straight crack path and thus lower elongation. On the contrary, running bond model shows a zigzag main crack. So, the main crack deflects frequently with high energy consumption. Furthermore, crack deflection into matrix cell increases propagation resistance, leading to the highest elongation in the running bond model. Therefore, the biomimetic bricks-and-mortar architecture delays and deflects main crack propagation. These findings have significant implication for the architecture design of advanced composite materials. [ABSTRACT FROM AUTHOR]

The elastocaloric effect in Cu–Al–Mn shape memory alloy microwires fabricated by Taylor–Ulitovsky method was investigated. The microwires with bamboo-like grain architecture, homogeneous composition and favorable orientation were successfully prepared through high-temperature annealing heat treatment. The formation of the bamboo grains and high specific surface area contribute to the reduced martensite transformation hysteresis. A large recoverable strain up to 8.8% was achieved by two-way shape memory cycling under a low stress of 50 MPa. Consequently, the microwire exhibited a large entropy change ΔSiso = 16.1 J kg−1 K−1. Furthermore, the refrigeration capacity (RC) reached ~ 502 J kg−1 over a working temperature interval ΔTFWHM = 31 K during direct transformation under 50 MPa uniaxial stress. Finally, a reversible adiabatic temperature change ΔTad = 3.9 K under a stress of 150 MPa was obtained. This proves that the present Cu–Al–Mn microwire, with bamboo grains, high refrigeration property and low cost, may act as promising candidate materials for elastocaloric cooling. [ABSTRACT FROM AUTHOR]

We have studied the effect of Co-doping on the microstructure, martensitic transformation, and magnetocaloric effect (MCE) of a Ni50Mn38Sb9Si3 alloy. Here, we further study the effect of Co-doping on the microstructure, martensitic transformation (MT), and MCE of Ni50Mn38Sb9Si3 alloy. The results show that phases α, β, and γ coexist in Ni50−xCoxMn38Sb9Si3 (x = 6, 12) alloys. The MT temperatures remain almost unchanged with the addition of Co element. Above the room temperature (RT), phase α exhibits MT under external magnetic fields up to 50 kOe, and possesses a great enhancement of ΔM from 0.008 emu/g in Ni50Mn38Sb9Si3 alloy to 21.4 emu/g in Ni38Co12Mn38Sb9Si3 alloy as well as an improvement of ∂M/∂T (obtained from M-T curves) that benefit ΔSM. The MT temperature intervals of M-T curves are enlarged from 3 K in the un-doped alloy to 11 K in the water-quenched Ni38Co12Mn38Sb9Si3 alloy attributed to the reduced coupling between magnetic and structural transition. This contributes to a magnetic entropy change (ΔSM) of 4.62 J/kg K and net refrigeration capacity (RCnet) of 18.5 J/kg under a magnetic field of 50 kOe, which is superior to that of the ferromagnetic compounds containing secondary precipitates. [ABSTRACT FROM AUTHOR]