Fatigue Behavior Of Mg Research Articles

Effect of extrusion ratio on microstructures, mechanical properties, and high cycle fatigue behavior of Mg–5Zn–1Mn alloy

The effects of extrusion ratio (ER) on the microstructures, static mechanical properties, and tension-compression high cycle fatigue (HCF) behavior of the as-extruded Mg–5Zn–1Mn (ZM51) alloy was investigated systematically, and the HCF mechanism was discussed. The results show that texture weakening and grain refinement caused by increasing the ER can effectively enhance the static mechanical properties and alleviate the tensile-compressive asymmetry of the alloy. The fatigue strength at 107 cycles is 124 ± 5, 138 ± 4, and 142 ± 5 MPa for ER8, ER11.5, and ER23, respectively, and the corresponding fatigue ratio is approximately 0.45, 0.49, and 0.50, which means that the as-extruded ZM51 alloy possesses outstanding fatigue resistance. The failure analysis and microstructure evolution of post-fatigued samples demonstrated that the stress amplitudes and microstructure characteristics strongly influence the HCF mechanism of the alloy. At high-stress load, close to the tensile yield strength 160–180 MPa, abundant {101‾2} residual twin bands were observed near the fracture surface. Twinning/detwinning deformation is the dominant fatigue mechanism due to the plastic deformation incompatibility between the matrix and the residual twins. At low-stress load, close to the fatigue strength 125–145 MPa, the fatigue crack initiation mechanism transits from twinning/detwinning to dislocation slip. Grain refinement and texture weakening inhibit the activation of {101‾2} twins, alleviate the twin-dislocation interaction, and promote dislocation slip to dominate the fatigue deformation, thereby enhancing the fatigue life of the alloy. This work provides new insight into the design and development for enhancing the fatigue resistance of wrought Mg alloy to ensure the long-term service safety of structural materials.

Impact of nano‐SiCP and nano‐hBNP on the corrosion performance and fatigue behavior of Mg–Zn hybrid nanocomposites

AbstractMagnesium (Mg) alloys are characterized by their high specific strength, strong damping resistance, and poor performance against corrosion. This study attempted to evaluate the corrosion capability and fatigue behavior of Mg–Zn alloys reinforced with nanosized silicon carbide (SiC) and hBN particles. Initially, different combinations (1.0 wt% nano‐SiCP [fixed] and 0.5, 1.0, and 1.5 wt% nano‐hBNP) of hybrid nanocomposites were synthesized through a stir‐ultrasonication casting process. The samples cut from the nanocomposites were subjected to salt spray, potentiodynamic polarization, tensile, and fatigue tests. The resistance to corrosion and fatigue characteristics of the monolithic alloy and hybrid nanocomposites were measured and compared. Due to the reduction in potential imbalance across the Mg‐α and I‐phases, the hybrid nanocomposites revealed enhanced corrosion performance as compared with the base alloy. The fatigue strength of the Mg–Zn alloy reinforced with 1% SiCP and 1.5% hBNP is about 94 MPa, which is 41% greater than the base alloy's fatigue strength. The scanning electron microscopy micrograph is helpful in investigating the microstructures of the corrosion, tensile, and fatigue‐tested samples.

Influence of heat treatment on cyclic deformation and low-cycle fatigue behavior of sand-cast Mg–10Gd–3Y–0.5Zr magnesium alloy

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Influence of different casting processes on high cycle fatigue behavior of Mg–10Gd–3Y–0.5Zr alloy

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Thermal fatigue behavior of Mg–9Al–Zn alloy with biomimetic strengthening units processed by laser surface remelting

Abstract Pulsed Nd:YAG laser was used to treat the surface of a magnesium alloy to improve the thermal fatigue resistance. The average grain size of the as-received material was reduced to ~3 μm and moreover β-Mg 17 Al 12 was precipitated in different forms. In addition, high density dislocation was acquired. The treated zone could efficiently prevent cracking on the sample surface. The crack growth was curbed within the treated zone and the microhardness increased by 80%. This enhancement was ascribed to the modified microstructural characteristics of the treated surface.

High-cycle fatigue behavior of Mg–Zn–Y–Zr alloy

This article presents the high-cycle fatigue behavior of an as-forged-T5 Mg–Zn–Y–Zr alloy with stress ratios of R = −1 and R = 0.1 at ambient temperature. The relationship between the maximum stress and the number of cycles to failure is established. The fatigue strength of the alloy at 10 7 cycles is strongly affected by both the heat treatment and the mean applied stress.

1311 固相合成法によるMg_2Si分散マグネシウム合金の疲労挙動(S21-1 軽金属の疲労,S21 金属材料の疲労特性と破壊機構)

1311 固相合成法によるMg_2Si分散マグネシウム合金の疲労挙動(S21-1 軽金属の疲労,S21 金属材料の疲労特性と破壊機構)