Effect of casting methods on microstructure and mechanical properties of ZM5 space flight magnesium alloy
The counter-gravity casting methods have been developed to remove the casting defects of Mg based alloys. However, the effects of different counter-gravity casting methods on the microstructure and mechanical properties have not been studied in detail. ZM5 alloys were prepared by gravity casting,...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Foundry Journal Agency
2018-11-01
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| Series: | China Foundry |
| Subjects: | |
| Online Access: | http://ff.foundryworld.com/uploadfile/2018121146755853.pdf |
| Summary: | The counter-gravity casting methods have been developed to remove the casting defects of Mg
based alloys. However, the effects of different counter-gravity casting methods on the microstructure and
mechanical properties have not been studied in detail. ZM5 alloys were prepared by gravity casting, low-pressure
casting and counter-pressure casting, respectively. The mechanical properties, microstructure and fracture
morphologies were examined and compared by means of optical microscopy, scanning electron microscopy
methods and tensile testing. Results show that casting defects such as gas pore, shrinkage porosity and cavity
can be eliminated by counter-pressure casting. The grain size of α-Mg is decreased signifi cantly by counterpressure
casting. Moreover, the precipitated particles are more uniform and fi ner in the counter-pressure casting
sample. As a result, the mechanical properties of the alloys are greatly improved. The tensile strength and
elongation of the samples by counter-pressure casting are 285 MPa and 13.9%, respectively, which are much
higher than those of the low pressure casting and gravity casting. |
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| ISSN: | 1672-6421 1672-6421 |