1. Evolution and Strengthening Effects of the Heat-Resistant Phases in Al–Si Piston Alloys with Different Fe/Ni Ratios.
- Author
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Meng, Fanchao, Wu, Yuying, Hu, Kaiqi, Li, Yang, Sun, Qianqian, and Liu, Xiangfa
- Subjects
HEAT resistant alloys ,FIELD emission electron microscopes ,ELECTRON probe microanalysis ,TENSILE strength ,ALLOYS ,PISTONS - Abstract
The evolution of three major heat-resistant phases (δ-Al
3 CuNi, γ-Al7 Cu4 Ni, T-Al9 FeNi) and its strengthening effects at high temperature in Al–Si piston alloys with various Fe/Ni ratios were studied using field emission scanning electron microscope (FE-SEM), electron probe microanalysis (EPMA), and X-ray diffraction (XRD). With the increase of Fe/Ni ratios, the heat-resistant phases begin to evolve in category, morphology, and distribution. The results show that a suitable Fe/Ni ratio will cause the T-Al9 FeNi phase to appear and form a closed or semi-closed network with δ-Al3 CuNi and γ-Al7 Cu4 Ni phases instead of the originally isolated heat-resistant phases. As a result, the ultimate tensile strength of the optimized alloy reached 106 MPa with a Fe/Ni ratio of 0.23, which was 23.3% higher than that of base alloy at 350 °C, which is attributed to the fact that a closed or semi-closed network microstructure is advantageous to the bearing of mechanical loads. This work may provide useful ideas for the development of high temperature resistant piston alloys. [ABSTRACT FROM AUTHOR]- Published
- 2019
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