中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 34 No. 8 August 2024 |
（1. School of Mechanical Engineering, Guizhou University, Guiyang 550025, China;
2. School of Mechanical Engineering, Dongguan University of Technology, Dongguan 523808, China;
3. Centro Nacional de Investigaciones Metalúrgicas (CENIM), C.S.I.C., Avda. de Gregorio del Amo 8, Madrid 28040, Spain;
4. Department of Chemical & Biotechnological Engineering, Université de Sherbrooke, Québec, QC J1K 2R1, Canada）
Abstract:Effects of ultrasonic vibration (UV) and mechanical vibration (MV) on the Mn-rich phase modification and mechanical properties of Al-12Si-4Cu-1Ni-1Mg-2Mn piston alloys were investigated. The results show that the UV and UV+MV treatments can significantly refine and fragmentize the microstructures. In addition, UV treatment can significantly passivate the primary Mn-rich Al15Mn3Si2 intermetallics. The formation mechanisms of refinement and passivation of the grains and non-dendrite particles were discussed. Compared with the gravity die-cast alloys, the UV and UV+MV treated alloys exhibit improved tensile and creep resistance at room and elevated temperatures. These results can be attributed to the refinement of the α(Al) grains and the secondary intermetallics, the increased proportion of refined heat-resistant precipitates, and the formation of nano-sized Si particles. The ultimate tensile strength of the UV treated alloys at 350 °C exceeds that of commercial piston alloys. This indicates the high application potential of the developed piston alloys in density diesel engines.
Key words: Al-Si piston alloys; Mn-rich phases; mechanical properties; ultrasonic vibration; mechanical vibration
