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The present study tested the effect of addition of whole common buckwheat flour on the rheological properties of wheat dough, and the textural characteristics, water distribution, secondary structure and molecular mass distribution of proteins, microstructure, and color of fresh noodles. The results demonstrated that the dough with 30% whole common buckwheat flour had a higher G’ (5.3 × 105 Pa) and a minimum tan δ value of 0.50. The resulting noodles had a maximum elasticity of 0.97, a maximum α-helix content of 28.30%, and a denser and more homogenous microstructure. According to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) data, the band intensities of buckwheat protein subunits increased with increasing addition of whole common buckwheat flour. Compared with the control group, the addition of whole common buckwheat flour caused partial transformation of tightly bound water to weakly bound water and free water. As the addition of common buckwheat flour increased, the L* value of noodles decreased significantly, the a* and b* values increased to varying degrees, and as a result the overall color turned reddish and yellow. In conclusion, the addition of 30% whole common buckwheat flour can improve the mechanical properties and processing quality of fresh noodles.

Summary: The inherent poor cooking quality and poor texture of mixed‐grain pasta limit consumer acceptance. This study systematically investigated the effect of curdlan in the processing of sweet potato puree oat mixed‐grain noodles, and comprehensively analysed a number of key indicators such as cooking characteristics, moisture state, texture properties, microstructure, starch crystallinity characteristics, short‐range ordered structure and thermal properties. At the production practice level, the study clearly indicated that the 0.6% curdlan addition ratio was the best solution in sweet potato puree oat mixed‐grain noodles processing. This finding not only significantly reduces the fracture rate, water absorption rate and cooking loss rate during the cooking process, but also significantly improves the quality and yield of the product, and brings significant improvement in the taste and texture of the noodles, which is of great significance for industrial production. In the microstructural and molecular studies, we revealed how curdlan could enhance the structural stability and mechanical strength of noodles by promoting the uniform distribution of starch granules in the gluten protein network. Further, through X‐ray diffraction, ordered structure and thermal property analyses, we have found that colchicine can effectively regulate the interactions of hydrogen bonding between starch and the content of straight‐chain and branched‐chain starch, which significantly reduces the crystallinity, ordered short‐chain structure and enthalpy of pasting of starch in the pasta. These in‐depth research results not only help us to understand more comprehensively the formation mechanism of the modification of pasta quality by curdlan, but also provide a solid theoretical foundation and practical guidance for the improvement of pasta quality in mixed grains. [ABSTRACT FROM AUTHOR]

To enhance the value proposition of sweet potato and oat while broadening their applicability in further processing, this study systematically investigated the impact of oat flour incorporation ratios (5%–25% of sweet potato dry weight) on the quality attributes of sweet potato–oat composite dough and its resulting steamed cake products. The results showed that the addition of oat flour could promote the rheological, water retention, and thermomechanical properties of the composite dough and improve the internal microstructure, specific volume, texture, and other processing properties of the steamed cake products. The rheology, water retention, and protein stability of the dough were maximized when the proportion of oat flour was 25%. The textural properties of steamed cakes, hardness, elasticity, cohesion, adhesion, chewiness, and recovery significantly increased (p < 0.05) and viscosity significantly decreased (p < 0.05) with the addition of oat flour. It is noteworthy that thermodynamic properties, internal structure of the dough, and air holding capacity, which are critical for processing, showed the best results at 20% oat flour addition. Therefore, the addition of 20%–25% oats is recommended to produce composite doughs with optimal quality and processing characteristics. Practical Application: As living standards improve, traditional cereals may no longer able to meet people's health needs. Therefore, there is an urgent consumer demand for nutritious, tasty alternatives to staple foods. In this study, oat flour and sweet potato mash were mixed to make sweet potato–oat cake, and the effect of ingredient ratio on the performance and quality of composite dough containing sweet potato–oat flour was analyzed, thus proposing an innovative approach to the research, development, and industrial production of sweet potato and oat food products. [ABSTRACT FROM AUTHOR]

A powder metallurgy (P/M) Ti-22Al-25Nb (at%) alloy was prepared by spark plasma sintering of pre-alloyed powders at 1000 °C/80 MPa/10 min. The solution treatments of the P/M Ti-22Al-25Nb alloy were conducted at a temperature range of 940–1030 °C at 30 °C intervals and holding times of 10 min, 30 min, 60 min, and 120 min. The effects of the solution temperature and the holding time on the microstructure evolution, B2 grain growth behavior, phase transition, tensile mechanical properties, and fracture behavior of the P/M Ti-22Al-25Nb alloy were systematically evaluated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction, and tensile tests. The results indicated that the microstructure and mechanical properties were closely linked to the solution temperature and the holding time. The effect of the holding time and the solution temperature on the B2 grain growth is well described by Beck's equation and Hillert's equation, respectively. The tensile tests showed that the tensile properties of the solution-treated P/M Ti-22Al-25Nb alloy were mainly affected by the number of O phases in the interior of the B2 grains and the phase transition degree of the α 2 phase at the grain boundary. The P/M Ti-22Al-25Nb alloy solution-treated at 940 °C/10 min exhibited the best mechanical properties at room temperature with a yield strength, tensile strength, and elongation of 867.8 MPa, 949.5 MPa, and 7.4%, respectively. A phase transition model of the α 2 phase was established. In addition, a tensile fracture model of the P/M Ti-22Al-25Nb alloy solution-treated under different conditions was established. • A powder metallurgy Ti-22Al-25Nb alloy was fabricated by spark plasma sintering. • Microstructure evolution and phase transition during solution treatment were studied. • B2 grain growth behavior of the solution-treated alloys was investigated. • A phase transition model of α 2 phase at the grain boundary was established. • Fracture mechanisms were analyzed and a fracture model was established. [ABSTRACT FROM AUTHOR]

The Al-8wt. % Si semi-solid billets were successfully prepared by a new liquid phase reaction sintering process with Al and Si elemental powders. The reaction mechanism of the Al and Si elemental powders was investigated, and the thermodynamics and dynamics of the reaction process were studied. The effect of the microstructure evolution on the mechanical properties was analyzed. In the reaction process, the reaction product Al(Si) (L) liquid phase wets the Al particles well, and the liquid phase content increased with increasing reaction temperature and time. It was found that the kinetic model given by ψ = 4.6 × 105exp(-1.05 × 105 /RT) t 1/3 can accurately predict the actual liquid phase formation fraction. With increasing reaction temperature, the viscosity of the liquid phase decreases and the Si atom diffusion coefficient increases. This will increase the formation rate of the liquid phase and decrease the length of lath Si. The increased liquid phase content increases the strength of the billet and decreases its elongation. The shear crack is the main reason for the instability of the billets during the deformation process. Acting as a crack source, Si particles accelerate the generation and propagation of cracks, and promote the instability fracture of the billet. • Al–Si semi-solid billet was prepared by a new method of LPS. • Microstructure and Si morphology evolution during reaction sintering were studied. • A reaction dynamic model is established by thermodynamic and kinetic analysis. • Al, Si reaction mechanism were analyzed and a mechanism model was established. • The effect of microstructure on mechanical properties was investigated. [ABSTRACT FROM AUTHOR]

Directional mass transport phenomena that differ from traditional sintering was found during microwave sintering of Ni Ti mixed powders, and the underlying magnetic-related mechanisms were analyzed, which benefitted from a newly developed experiment setup that combining a single-model microwave cavity with the synchrotron radiation computed tomography (SR-CT) system. The electric and magnetic fields (H-fields) of microwave can be separated and their direction and amplitude become quantifiable and definitive by using the single-mode microwave cavity, and the microstructure evolution of matter in separate H-field can be online observed by the SR-CT technique. The experimental results showed the presence of special mass transport from Ti particle to Ni particle. It may be caused by different magnetic energy loss in Ni and Ti particles due to their different dielectric properties. The mass transport from Ti to Ni was found to have unequal rates in different directions, which may be caused by the polarization direction of H-field. This study may provide some inspiration for fabricating new metallic materials with oriented microstructure and property by using microwave H-field. It also proves the effectiveness of the single-mode microwave cavity SR-CT experimental setup and provides a new way for in-depth investigation on microwave interaction with matter. [ABSTRACT FROM AUTHOR]

In the present study, repetitive upsetting-extrusion (RUE) process was employed to induce severe plastic deformation (SPD) for an AZ91D magnesium alloy at temperatures ranging from 285 °C to 380 °C. Finite element method (FEM) and technical experiment were performed to reveal the non-uniform behavior during the RUE process. The results from the finite element analysis showed that effective strain was unevenly distributed in one-cycle strained sample and the non-uniformity would exist permanently with increasing deformation cycles. The microstructure evolution of the RUE processed alloys was characterized by optical microscopy, which clarified the microstructural development from heterogeneous and coarse as-cast structure, heterogeneous and refined structure to final homogeneous and fine-grained structure of the 340 °C and eight-cycle processed sample. In addition, a critical strain was suggested from the metallographic observation results. It was proposed that α -Mg grain structure was sufficiently refined by imposing accumulated strain beyond the critical value and the invariability of grain sizes was illustrated. A homogeneous structure with mean grain size of ∼3.04 μm was obtained after 285 °C and three-cycle RUE process, corresponding to an accumulated true strain of about 3.75. Furthermore, the fragmentation and dispersed distribution of the β -Mg 17 Al 12 phase induced by shearing was confirmed by referring to scanning electron microscope (SEM) examination. Moreover, refining mechanisms responsible for grain structure were discussed in detail with reference to the transmission electron microscope (TEM) analysis results. [ABSTRACT FROM AUTHOR]

Lightweight TiAlV 0.5 CrMo refractory high-entropy alloy (RHEA) with ultra-fine grains was initially fabricated by mechanical alloying (MA) and subsequent spark plasma sintering (SPS). The microstructural evolution, mechanical performance and strengthening mechanisms of the alloys in various processing conditions were systematically characterized. A single body-centered cubic (BCC) solid solution phase with nanocrystalline structure was formed after milling for 30 h. Afterward, the BCC2 and Al 2 O 3 phases were precipitated from the supersaturated BCC structure during the sintering process in the temperature range from 1100 to 1300 °C. The specimen with an average grain size of ∼0.47 µm and an precipitation phase of less than ∼0.15 µm was obtained at sintering temperature of 1200 °C, exhibiting ultra-high micro-hardness of 10.26 GPa, acceptable compressive yield strength of 1825 MPa, outstanding ultimate compressive strength of 2989 MPa and satisfactory plastic strain of 17.8% at room temperature. The excellent mechanical properties of the TiAlV 0.5 CrMo RHEA were dominantly attributed to the combined effects of inherent solid solution strengthening, grain boundary strengthening and precipitation strengthening. It is anticipant that the process of combining MA and SPS is the effective method to produce novel lightweight and refractory structural material with outstanding performance. • Novel lightweight TiAlV 0.5 CrMo RHEAs with ultra-fine grains were synthesized by MA and SPS. • Multiphase microstructure with BCC1, BCC2, and Al 2 O 3 phases was formed during SPS. • The RHEAs exhibited a compressive yield strength of 1825 MPa and a plastic strain of 17.8%. • The strength-ductility trade-off in RHEAs was controlled by grain boundary strengthening and precipitation strengthening. [ABSTRACT FROM AUTHOR]

TiAl-based alloys with high melting point become the promising high temperature structural materials, but the inherent brittleness drawback suppresses their application. Here, we proposed a controllable strategy to concurrently achieve high strength and high plasticity in TiAl/Nb composites that were prepared by introducing fine plastic Nb particulates to disperse around matrix TiAl, followed by powder metallurgy reaction at 1200 °C/50 MPa/1 h. A complex atomic diffusion reaction (ADR) at the interfaces between matrix TiAl and plasticizer Nb was clarified. The results of uniaxial compression of TiAl/Nb composites at room temperature (RT) show the high strength and excellent plasticity, due to the operation of multiple deformation mechanisms of involved phases in the novel structure. Definitely, the prominent deformation mechanism of matrix TiAl was 1 / 6 11 2 ¯ ] 111 ss-slip. The plasticizer, such as fresh Nb-based intermetallics (Nb im) and remained Nb (Nb r), coordinated the overall migration of matrix particulates in the form of compatible deformation. The strengthening phase O/B2 belonged to the dislocation-mediated deformation and was responsible to propagate stress from the plasticizer to the matrix. Predominantly, the tailoring microstructure that Nb im /Nb r was interspersed in the fresh γ n and O/B2 was conducive to the successive straining of the composites, which in turn facilitated the intersection or entanglement of the proliferating dislocations and thereby resulted in high strength. • The TiAl/Nb composites with high strength and high plasticity were prepared by PM method. • The mechanism of ADR at the heterogeneous TiAl/Nb interfaces was elaborated. • The tailoring microstructure that the hard matrix particles were encapsulated by the relatively soft IPs was obtained. • The deformation mechanism of TiAl/Nb composites was clarified, especially the deformation twinning in the matrix phase. [ABSTRACT FROM AUTHOR]