Lijie Zuo

Evaluating the dynamic responses of submarine cable pallets is of considerable importance in engineering applications. Nevertheless, an effective mechanical model to capture the dynamic responses of the pallet has yet to be developed. Therefore, a dynamic model of a submarine cable pallet was built, and the dynamic responses were studied in this paper. Elastic springs were arranged horizontally between the inner and outer fences. The objective was to replace the submarine cable with springs while accounting for the interaction between the submarine cable and the pallet during the falling process. First, the necessity of incorporating the submarine cable into the model was validated through analyzing the dynamic responses of the pallet under varying submarine cable mass conditions. Subsequently, the dynamic responses of the pallet under various falling postures were examined, with a focus on the effects of fall velocity and angle. Finally, the dynamic stability of the pallet was determined based on displacement mutation criteria during the falling process. The results demonstrated that the displacement of the pallet web plate initially increased and subsequently decreased with the increase in submarine cable mass, whereas the displacement of the fence exhibited a clearly upward trend. Both fall velocity and angle exerted significant influences on the dynamic responses of the pallet. In conclusion, this study provided a theoretical foundation and practical reference for the stability assessment and engineering application of submarine cable pallets.

Cu–Al alloys are widely used in electronics, new energy, and other fields due to the combination of th excellent corrosion resistance and electrical conductivity of Cu and the light weight of Al. In this paper, the powder metallurgy and equal-channel angular pressing compound technology was used to fabricate a Cu–Al alloy joint, which can be used to replace armor. Devices such as an optical microscope, electron scanning microscope, and microhardness scale were used to characterize the microstructure and mechanical properties of the Cu–Al alloys. The finite element analysis software Abaqus was used to analyze stress distribution during equal-channel angular pressing. The results indicated that the microstructure and properties of Cu–Al alloys were closely related to the volume ratio of Cu–Al. The microhardness and tensile strength were significantly increased by increasing the volume ratio of Cu–Al. As the volume ratio of Cu–Al varied from 1:2 to 2:1, the ultimate tensile strength of the Cu–Al alloys increased from 79.9 MPa to 164.9 MPa at room temperature and the microhardness increased from 60 HV to 101 HV. However, the elongation of the Cu–Al alloys hardly changed; this was about 4.4%. Crack initiation occurred at the Cu–Al interface and spread along the bonding surface of the Cu–Al alloys during the tensile process.

The effects of Fe, Cr and thermal exposure on the microstructure and mechanical properties of Al-Si alloy were investigated in this work. The results indicated that the main phases of the Al-Si-Cu-Ni-Mg-(0.6–0.9%) Fe (wt. %) alloy were α-Al, Si, Al₅Cu₂Mg₈Si₆, Al₃CuNi, Al₇Cu₄Ni, Al₂Cu, and AlFeSi at room temperature. The size of the AlSiFe phase increased with increasing the weight fraction of Fe. The shape of Fe-rich phase changed from rod-like to star-like, followed by long needle-like with Fe varying from 0.6% to 0.9%. The mechanical properties of the studied alloys at elevated temperatures increased with Fe. The ultimate tensile strength of the three alloys at 350 °C was 111.2 MPa, 124 MPa, and 128.7 MPa, respectively. In addition, the ductility and strength of the studied alloys at room temperature decreased with increasing the Fe, due to the large size of the hard and brittle Fe-rich phase strictly cleaved the aluminum matrix. After thermal exposure, the properties of the alloy at room temperature and elevated temperature decreased obviously at the beginning of 0.5~8 h, and then tend to be stabilized during thermal exposure at 350 °C for approximately 32~64 h. Fe-rich was a thermal stable phase at 350 °C.

Due to exceptional conductivity, lightweight nature, corrosion resistance, and various other advantages, Cu/Al bimetallic composites are extensively utilized in the fields of communication, new energy, electronics, and other industries. To solve the problem of poor metallurgical bonding of Cu/Al bimetallic composites caused by high-temperature oxidation of Cu, different coating thicknesses of Ni layer on Cu rods were used to fabricate the Cu/Al bimetallic composite by gravity casting. The effect of liquid–solid volume ratio and coating thickness on microstructure and properties of a Cu/Al bimetallic composite were investigated in this study. The results indicated that the transition zone width increased from 242.3 μm to 286.3 μm and shear strength increased from 17.8 MPa to 30.3 MPa with a liquid–solid volume ratio varying from 8.86 to 50. The thickness of the transition zone and shear strength increased with the coating thickness of the Ni layer varying from 1.5 μm to 3.8 μm, due to the Ni layer effectively preventing oxidation on the surface of the Cu rod and promoting the metallurgical bonding of the Cu/Al interface. The presence of a residual Ni layer in the casted material hinders the diffusion process of the Cu and Al atom. Therefore, the thickness of the transition zone and shear strength exhibited a decreasing trend as the coating thickness of the Ni layer increased from 3.8 μm to 5.9 μm. Shear fracture observation revealed that the initiation and propagation of shear cracks occurred within the transition zone of the Cu/Al bimetallic composite.

(AlFeNiCrCoTi0.5)p/6061Al matrix composites were prepared by cold isostatic pressing combined with equal-diameter angular extrusion. The microstructure and properties of the extruded materials after adding high-entropy alloys were studied. The FCC + BCC dual-phase high-entropy alloy particles mechanically alloyed for 90 h were added to the aluminum matrix, while the composite material formed a diffusion interface after equal-diameter angular extrusion. Compared with the 6061Al matrix, when the content of AlFeNiCrCoTi0.5 was 10%, by two passes, the hardness increased from 52.5 HV to 70.3 HV, the tensile strength increased from 158 MPa to 188 MPa, and the elongation changed from 14.9% to 14.1%. The material had good comprehensive mechanical properties.