In this study, the wear behavior of a heat-treatable Al-7Si-0.5Mg-0.5Cu alloy fabricated by selective laser melting was investigated systematically. Compared with the commercial homogenized AA2024 alloy, the fine secondary phase of the SLM Al-Cu-Mg-Si alloy leads to a low specific wear rate (1.8 ± 0.11 × 10−4 mm3(Nm)−1) and a low average coefficient of friction (0.40 ± 0.01). After the T6 heat treatment, the SLM Al-Cu-Mg-Si alloy exhibits a lower specific wear rate (1.48 ± 0.02 × 10−4 mm3(Nm)−1), but a similar average coefficient of friction (0.34 ± 0.01) as the heat-treated AA2024 alloy. Altogether, the SLM Al-3.5Cu-1.5Mg-1Si alloy is suitable for the achievement of not only superior mechanical performance, but also improved tribological properties.

As an intelligent material, magnetorheological fluid (MRF) is used in various applications, such as vibration dampers and automotive engine mounts. In order to study the influence of MRF composition parameters on vibration transfer characteristics, this paper proposes an MRF vibration transmission equivalent model based on the analysis of the interaction between carbonyl iron particles (CIPs) and carrier liquid, calculates the vibration transfer power flow level difference (PLD) of MRF with different composition parameters, and performs experimental verification. The results show that when only the particle diameter changes, the PLD peak increases with increasing particle diameter, and the PLD peak frequency shifts to lower frequencies. When the particle volume fraction gradually increases, and the remaining parameters are kept constant, the PLD peak increases first and then decreases, and the peak frequency shifts to high frequencies. When changing only the carrier liquid viscosity, the PLD peak decreases as the viscosity increases, while the peak frequency is shifted toward the high frequency. The MRF has a maximum frequency shift of 61.6Hz when the particle diameter, particle volume fraction, and carrier liquid viscosity are 8μm, 20% and 0.3 Pa·s, respectively. It is shown that adjusting the composition parameters can change the PLD and vibration suppression band of MRF, and using this feature can help improve the broadband vibration suppression performance of MR devices and the vibration suppression efficiency under specific working conditions, further expanding the application of MRF in the field of vibration control.

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