Copper-coated carbon fibers have excellent conductivity and mechanical properties, making them a promising new lightweight functional material. One of the main challenges to their development is the poor affinity between carbon fiber and metals. This paper selects different carbon fibers for copper electroplating experiments to study the effect of carbon fiber properties on the interface bonding performance between the copper plating layer and carbon fibers. It has been found that the interfacial bonding performance between copper and carbon fiber is related to the degree of graphitization of carbon fiber. The lower the degree of graphitization of carbon fiber, the smaller the proportion of carbon atoms with sp2 hybrid structure in carbon fiber, the stronger the interfacial bonding ability between carbon fiber and copper coating. Therefore, carbon fiber with lower graphitization degree is conducive to reducing the falling off rate of copper coating and improving the quality of copper coating, and the conductivity of copper-plated carbon fibers increases with the decrease of graphitization degree of carbon fibers. The conductivity of copper-plated carbon fibers increases by more than six times when the graphitization degree of carbon fibers decreases by 23.9%. This work provides some benchmark importance for the preparation of highquality copper-plated carbon fibers.

In this work, the trend in the performance of carbon fiber (CF) and its composite during self-polymerization of polydopamine (PDA) at carbon fiber surface was investigated by varying the self-polymerization time of dopamine in an aqueous solution. Research has shown that the PDA coating elevated the surface roughness and polarity of the inert fiber. The tensile strength of single carbon fiber was significantly improved, especially after 9 h of polydopamine self-polymerization, increasing by 18.64% compared with that of desized carbon fiber. Moreover, the interlaminar shear strength (ILSS) of CF-PDA9-based composites was 35.06% higher than that of desized CF-based composites. This research will provide a deep insight into the thickness and activated ingredients of dopamine oxidation and self-polymerization on interfacial compatibility of carbon fiber/epoxy resin composites.

This study investigated the growth behavior and characteristics of compounds formed at the interface between a liquid Al-Si-Cu alloy and solid cast iron. Through microstructural analyses, it was observed that various AlFe and AlFeSi phases are formed at the interface, and the relative proportion of each phase changes when small amounts of strontium are added to the Al alloy. The results of the microstructural analysis indicate that the primary phases of the interfacial compounds in the Al-Si-Cu base alloy are Al8Fe2Si and Al4.5FeSi. However, in the Sr-added alloys, significant amounts of binary AlFe intermetallic compounds such as Al5Fe2 and Al13Fe4 formed, in addition to the AlFeSi phases. The inclusion of Sr has a slight diminishing effect on the rate at which the interfacial compounds layer thickens during the time the liquid Al alloy is in contact with the cast iron. The study also discusses the nano-indentation hardness and micro-hardness of the interfacial phases.

The engineered barrier system (EBS) is an indispensable element of a deep geological repository (DGR) designed to prevent the discharge of radioactive materials into the environment. The buffer material is a vital component of the EBS by creating a physical and chemical barrier that prevents the migration of radioactive materials. In the disposal environment, gases can be generated from the corrosion of the canister. When the gas generation rate exceeds the diffusion rate, the buffer material’s performance can deteriorate by the physical damage induced by the increase in pore pressure. Therefore, understanding the EBS’s behavior under gas generation conditions is crucial to guarantee the longterm safety and performance of the DGR. Lab-scale and field-scale experiments have been conducted to examine the stability of the buffer material concerning gas generation and movement by the previous researchers. To evaluate long-term stability for more than 100,000 years, it is essential to assess stability using a numerical model verified by these experiments. This study investigated the effect of interfacial characteristics on the numerical modeling accuracy of experimental simulation while verifying a numerical model through field-scale experimental results. The findings of this study are expected to furnish fundamental data for establishing numerical analysis guidelines for the longterm stability assessment of disposal systems.

In order to broaden the range of application of light weight aluminum alloys, it is necessary to enhance the mechanical properties of the alloys and combine them with other materials, such as cast iron. In this study, the effects of adding small amounts of Cu and Zr to the Al-Si-Mg based alloy on tensile properties and corrosion characteristics were investigated, and the effect of the addition on the interfacial compounds layer with the cast iron was also analyzed. Although the tensile strength of the Al-Si-Mg alloy was not significantly affected by the additions of Cu and Zr, the corrosion resistance in 3.5 %NaCl solution was found to be somewhat lowered in this research. The influence of Cu and Zr addition on the type and thickness of the interfacial compounds layer formed during compound casting with cast iron was not significant, and the main interfacial compounds were identified to be Al5FeSi and Al8Fe2Si phases, as in the case of the Al-Si-Mg alloys.