Microstructure and Mechanical Properties of WE43A Rare Earth Magnesium Alloys with Loose Defects AITranslate
Abstract AITranslate
WE43A rare earth magnesium alloy possesses advantages in terms of high specific strength，specific stiffness，and high temperature resistance，making it highly beneficial for lightweighting aerospace applications. It finds extensive use in aviation，aerospace，and related fields，such as helicopter frames，aircraft wings，and compressor casings. According to statistics，the majority of magnesium alloy components （90%） are produced through casting，which inevitably leads to the occurrence of porosity defects within the magnesium alloy. Even a small amount of porosity defects can cause a significant decrease in mechanical performance. This is due to the reduction in the effective load-bearing area of the castings caused by the presence of porosity defects，resulting in stress concentration and the initiation and propagation of fatigue cracks under cyclic loading conditions. As a result，the fatigue performance of critical load-bearing castings is compromised，leading to premature failure and severe consequences. In general，the generation of defects can be minimized by implementing techniques such as centrifugal casting and controlling the solidification temperature. Centrifugal casting promotes grain growth，thereby reducing defects associated with grain boundaries and producing a more uniform and dense material structure. Additionally，controlling the solidification temperature allows for the adjustment of the solidification rate，preventing defects caused by excessively high or low local temperatures and improving the overall quality of the material. However，there has been limited systematic investigation on the mechanical properties of materials with defects. Therefore，it is necessary to analyze and study the mechanical properties and changes of WE43A rare earth magnesium alloy containing porosity defects. In this study，WE43A rare earth magnesium alloy was selected as the research subject，and the samples were graded and screened to obtain specimens that meet the defect level requirements for subsequent mechanical property testing. This was achieved by increasing the probability of defect occurrence through process adjustments and directly selecting samples from a large number of production products to obtain specimens that conform to the defect level requirements. X-ray non-destructive testing was an efficient and accurate quality inspection method that played a crucial role in magnesium alloy castings. This technique provided internal structural imaging information of the samples，enabling comprehensive assessment of internal quality. According to the "Specification for Magnesium Alloy Castings"，five defect levels （I to V） were defined to describe the severity of porosity defects. Sponge-like and dispersed forms were two typical types of porosity defects. Four-point bending fatigue tests were performed on specimens with dimensions of approximately （7.4±0.1） mm in thickness，（21.0±0.1） mm in width，and （82.2±0.1） mm in length. The fatigue specimens were plate-shaped，supported by rollers，with a roller diameter of 10 mm，and a pressure roller was used to apply an average stress of 100 MPa at a loading frequency of 20 Hz. Tensile tests were conducted on rod-shaped specimens with a diameter of approximately （5.00±0.02） mm and a length of （110±0.1） mm using an MTS electronic universal testing machine. The tensile tests were carried out in accordance with HB5143，with a strain rate of 0.00025 s−1. Metallographic analysis of the alloy was performed using an XJP-3Ad metallographic microscope （OM）. Scanning electron microscopes （SEM），including S-3400N-type and SU1510-type，were utilized to observe the fracture morphology. The influence of different types and degrees of defects on the mechanical properties of rare earth magnesium alloys was systematically investigated，and the formation mechanism and control strategies of defects were discussed. This provided a theoretical basis for improving the casting quality and efficiency of rare earth magnesium alloys. The study of internal defects in alloys and further understanding of the destructive effects of defects had both theoretical and practical significance. The results indicated that the porosity defects mainly existed as irregular strip-like and elliptical voids at grain boundaries. With increasing defect levels，the area of porosity defects within the specimens continuously increased from 0.8% to 30%. The tensile strength，yield strength，and elongation of WE43A magnesium alloy exhibited a decreasing trend with increasing defect levels，with the decrease in elongation being slightly smaller than that in tensile strength. The average tensile strength of specimens with defect Level Ⅰ was approximately 260 MPa，which decreased to 80 MPa when the defect level reached Ⅴ. The yield strength decreased from 180 to 70 MPa. The reductions in tensile strength and yield strength were 70.71% and 62.22%，respectively，while the decrease in elongation was 41.56%. The average fatigue logarithmic life （lgN） of specimens with defect Level Ⅴ decreased by 28.17% compared to that of defect-free specimens. The average fatigue limit of specimens with defect Level Ⅴ decreased by 38.09% compared to that of defect-free specimens. The fatigue fracture exhibited cleavage feature；a small amount of porosity （defect Level Ⅰ） had a minor effect on the mechanical properties of the material. When the porosity content was low，there was little difference in tensile strength，yield strength，elastic modulus，and defect-free magnesium alloy. However，a noticeable decrease in mechanical performance occurred when the defect level reached Ⅱ. The excessive porosity defects significantly reduced the material's ductility.
KeyWords AITranslate
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Basic Information:
DOI：10.13373/j.cnki.cjrm.XY23090022
Chinese Library Classification Number:TG146.2
Citation Information:
WE43A rare earth magnesium alloy possesses advantages in terms of high specific strength，specific stiffness，and high temperature resistance，making it highly beneficial for lightweighting aerospace applications. It finds extensive use in aviation，aerospace，and related fields，such as helicopter frames，aircraft wings，and compressor casings. According to statistics，the majority of magnesium alloy components （90%） are produced through casting，which inevitably leads to the occurrence of porosity defects within the magnesium alloy. Even a small amount of porosity defects can cause a significant decrease in mechanical performance. This is due to the reduction in the effective load-bearing area of the castings caused by the presence of porosity defects，resulting in stress concentration and the initiation and propagation of fatigue cracks under cyclic loading conditions. As a result，the fatigue performance of critical load-bearing castings is compromised，leading to premature failure and severe consequences. In general，the generation of defects can be minimized by implementing techniques such as centrifugal casting and controlling the solidification temperature. Centrifugal casting promotes grain growth，thereby reducing defects associated with grain boundaries and producing a more uniform and dense material structure. Additionally，controlling the solidification temperature allows for the adjustment of the solidification rate，preventing defects caused by excessively high or low local temperatures and improving the overall quality of the material. However，there has been limited systematic investigation on the mechanical properties of materials with defects. Therefore，it is necessary to analyze and study the mechanical properties and changes of WE43A rare earth magnesium alloy containing porosity defects. In this study，WE43A rare earth magnesium alloy was selected as the research subject，and the samples were graded and screened to obtain specimens that meet the defect level requirements for subsequent mechanical property testing. This was achieved by increasing the probability of defect occurrence through process adjustments and directly selecting samples from a large number of production products to obtain specimens that conform to the defect level requirements. X-ray non-destructive testing was an efficient and accurate quality inspection method that played a crucial role in magnesium alloy castings. This technique provided internal structural imaging information of the samples，enabling comprehensive assessment of internal quality. According to the "Specification for Magnesium Alloy Castings"，five defect levels （I to V） were defined to describe the severity of porosity defects. Sponge-like and dispersed forms were two typical types of porosity defects. Four-point bending fatigue tests were performed on specimens with dimensions of approximately （7.4±0.1） mm in thickness，（21.0±0.1） mm in width，and （82.2±0.1） mm in length. The fatigue specimens were plate-shaped，supported by rollers，with a roller diameter of 10 mm，and a pressure roller was used to apply an average stress of 100 MPa at a loading frequency of 20 Hz. Tensile tests were conducted on rod-shaped specimens with a diameter of approximately （5.00±0.02） mm and a length of （110±0.1） mm using an MTS electronic universal testing machine. The tensile tests were carried out in accordance with HB5143，with a strain rate of 0.00025 s−1. Metallographic analysis of the alloy was performed using an XJP-3Ad metallographic microscope （OM）. Scanning electron microscopes （SEM），including S-3400N-type and SU1510-type，were utilized to observe the fracture morphology. The influence of different types and degrees of defects on the mechanical properties of rare earth magnesium alloys was systematically investigated，and the formation mechanism and control strategies of defects were discussed. This provided a theoretical basis for improving the casting quality and efficiency of rare earth magnesium alloys. The study of internal defects in alloys and further understanding of the destructive effects of defects had both theoretical and practical significance. The results indicated that the porosity defects mainly existed as irregular strip-like and elliptical voids at grain boundaries. With increasing defect levels，the area of porosity defects within the specimens continuously increased from 0.8% to 30%. The tensile strength，yield strength，and elongation of WE43A magnesium alloy exhibited a decreasing trend with increasing defect levels，with the decrease in elongation being slightly smaller than that in tensile strength. The average tensile strength of specimens with defect Level Ⅰ was approximately 260 MPa，which decreased to 80 MPa when the defect level reached Ⅴ. The yield strength decreased from 180 to 70 MPa. The reductions in tensile strength and yield strength were 70.71% and 62.22%，respectively，while the decrease in elongation was 41.56%. The average fatigue logarithmic life （lgN） of specimens with defect Level Ⅴ decreased by 28.17% compared to that of defect-free specimens. The average fatigue limit of specimens with defect Level Ⅴ decreased by 38.09% compared to that of defect-free specimens. The fatigue fracture exhibited cleavage feature；a small amount of porosity （defect Level Ⅰ） had a minor effect on the mechanical properties of the material. When the porosity content was low，there was little difference in tensile strength，yield strength，elastic modulus，and defect-free magnesium alloy. However，a noticeable decrease in mechanical performance occurred when the defect level reached Ⅱ. The excessive porosity defects significantly reduced the material's ductility.
quote
| GB/T 7714-2015 | [1] Zhenwei Wei, Zifeng Wang, Aihua Zou, et al. Microstructure and Mechanical Properties of WE43A Rare Earth Magnesium Alloys with Loose Defects[J]. Chinese Journal of Rare Metals, 2025, 49(2): 153-162. DOI:10.13373/j.cnki.cjrm.XY23090022. |
| MLA | [1] Zhenwei Wei, et al., "Microstructure and Mechanical Properties of WE43A Rare Earth Magnesium Alloys with Loose Defects." Chinese Journal of Rare Metals, vol. 49, no. 2, 2025, pp. 153-162, https://doi.org/10.13373/j.cnki.cjrm.XY23090022. |
| APA | [1] Zhenwei Wei, Zifeng Wang, Aihua Zou, Zhipeng Li, Heng Wang, Wei Zhao, Guangshan Yang, & Changkui Liu. (2025). Microstructure and Mechanical Properties of WE43A Rare Earth Magnesium Alloys with Loose Defects. Chinese Journal of Rare Metals, 49(2), 153-162. https://doi.org/10.13373/j.cnki.cjrm.XY23090022 |
| IEEE | [1] Zhenwei Wei, Zifeng Wang, Aihua Zou, Zhipeng Li, Heng Wang, Wei Zhao, Guangshan Yang, and Changkui Liu, "Microstructure and Mechanical Properties of WE43A Rare Earth Magnesium Alloys with Loose Defects," Chinese Journal of Rare Metals, vol. 49, no. 2, pp. 153-162, 2025, doi: 10.13373/j.cnki.cjrm.XY23090022. keywords: {WE43A magnesium alloy;defect morphology;mechanical properties;fatigue life prediction model} |