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| Effects of Sr and ultrasonic vibration on microstructures and
mechanical properties of ascast A380 alloy |
| 1. College of Mechanical and Vehicle Engineering, Hunan University, Changsha, Hunan 410082, China; 2. School of Mechanical Engineering, Hunan International Economics University, Changsha, Hunan 410205, China; 3. School of Materials Science and Engineering, Central South University, Changsha, Hunan 410083, China |
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Abstract The effects of 0～0.25% Sr and ultrasonic vibration (UV) on microstructure and mechanical properties of A380 alloy were investigated. The results show that the microstructure in A380 alloy can be refined significantly, and the αAl phase are changed from coarse dendrite into fine nondirectional dendrites with globular structure, while the eutectic Si phase are changed from coarse acicular into vermicular, spot ones and fibrous. The desirable refinement of the microstructure in A380 alloy is obtained with 0.15% Sr. Tensile strength, yield strength, elongation and hardness of the ascast A380 with 0.15% Sr addition are 305 MPa, 219 MPa, 3.78% and 106 BHN, and those are respective 318 MPa, 227 MPa, 3.99% and 108 BHN under 0.15% Sr addition with UV. The smallest grain size is 42 μm, and the largest shape factor is 0.71 with 0.15% Sr addition under UV.
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Received: 26 May 2017
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2018, Vol. 39 
