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to the mechanical causes. Among casting defects, porosity is considered the key factor controlling the fatigue behavior of Al-based castings since they are preferential sites for crack initiation, independent... evaluation since both pores area fraction and their geometrical characteristics are important as fatigue crack risers. In fact, it is well known that mechanical properties of Al-Si alloys depend......
boundary conditions were used in both x and y directions so the sample represented a free-standing thin-film of "bicrystal" with a GB in between. A crack tip was introduced on one surface of the sample. The crack tip was used as a dislocation source when the slab was under tensile loading. The samples were prepared by full relaxation at chosen temperatures (10 K in our case) in NPT ensemble using......
al [13] identified the mechanism of multi-scale fatigue crack propagation of nickel-based alloy GH4169 with different grain sizes by using the specimens with micro-notches. The results indicated that grain size effect on the growth rate of small crack could not be distinguished due to the fluctuation of crack growth rate and the small fatigue crack stage accounted for a larger fraction......
. When the sink moves, it may not be able to communicate with the proxy sensor. In order to solve this problem, the sink records all the nodes in its moving path, and each of the nodes only records its prior sensor and the next sensor in the path. As shown in Fig.3, the sink chooses node A as its proxy sensor. When it moves out of the communication range of node A, it will choose node B from......
at a near-constant stress of 100 MPa to form a plateau along <0001> loading path due to the activity of tension twin (Fig. 8(e)). As the plastic deformation proceeds until a strain of about 6.5... and compression loading are quite asymmetric. For instance, the flow stress along tension path is 175 MPa due to the activity of prismatic slip. But the flow stress along compression path is 140......
层有可能的热分解路径及其产物(见图6)进行了全面系统的分析,并对每一条路径所对应的分解焓ΔHd进行计算,如式(2)~(7)所示: 图6 FCC-Cr1-xAlxN(x=0~1)涂层的热分解路径 Fig. 6 Thermal decomposition paths of FCC-Cr1-xAlxN (x=0-1) coating ΔHd(path 1)=(1-x)Etot(FCC-CrN)+xEtot(FCC-AlN)- Etot(FCC-Cr1-xAlxN) (2) ΔHd(path 2)=(1-x......
centimeter-scale, the seepage path of the model can be divided into four types: homogeneous seepage (Model I), reticular- homogeneous seepage (Model II), finger-reticular seepage (Model III) and finger... average displacement volume of 0.014 cm3. 4.3 Finger-reticular seepage As shown in Figs. 4(e), (f), and Table 1, after water is injected into the saturated oil model, the main displacement path......
fracture toughness of 7150- T7751, for example, has been attributed largely to its un-recrystallised microstructure (giving a more tortuous crack propagation path) and its reduced volume fraction......
without any visible defects such as pinhole, tunnel defect, crack, void, surface groove and surface galling. It has been observed that when tool rotation speed is lower than 1000 r/min, tunnel defect... a crucial role in material flow during welding. The relationship between the static and dynamic volumes of the tool pin decided the path for the flow of plasticized material from the leading edge......
, crack deflection and whisker pullout. In the sample, AlFe grains with about tens of nanometers in diameter can be seen in some Al2O3 grains or at grain boundaries (as shown by arrow 2 in Fig.3(c)). The particulates can improve the toughness of the material too. The toughening mechanisms are mainly interface debonding and crack deflection. The chemical combination about Al2OC and AlFe releases energy......