Chen Gaohong, Yu Mei, Dong Hongrui, Liu Jianhua
Beijing Institute of Aeronautical Materials, Beijing 100095, China.
School of Materials Science and Engineering, Beihang University, Beijing 100191, China.
Materials (Basel). 2024 Aug 7;17(16):3918. doi: 10.3390/ma17163918.
Graphene has been considered an ideal reinforcement in aluminum alloys with its high Young's modulus and fracture strength, which greatly expands the application range of aluminum alloys. However, the dispersion of graphene and the interfacial reaction between graphene and the aluminum matrix limit its application due to elevated temperature. Friction stirring processing (FSP) is regarded as a promising technique to prepare metal matrix composites at lower temperatures. In this paper, FSP was used to prepare graphene-nanoplates-reinforced aluminum composites (GNPs/Al). The corresponding effects of the process parameters and graphene content on GNPs/Al were thoroughly studied. The results showed that plastic strain, heat input, and graphene content were the key influencing factors. Large degrees of plastic strain can enhance the dispersion of graphene by increasing the number of stirring passes and the ratio of stirring to welding velocity, thereby improving the strength of GNPs/Al. Low heat input restricts the plastic flow of graphene in the matrix, whereas excessive heat input can promote interfacial reactions and lead to the formation of a more brittle phase, AlC. This is primarily associated with the stirring velocity and welding velocity. High graphene content levels can improve the material strength by refining the grain size, improving the load transfer ability, and acting as a precipitate to prevent dislocation movement. These findings make a contribution to the development of advanced aluminum alloys with graphene reinforcement, offering broader application potential in industries.
石墨烯因其高杨氏模量和断裂强度，被认为是铝合金中理想的增强材料，这极大地扩展了铝合金的应用范围。然而，由于温度升高，石墨烯的分散以及石墨烯与铝基体之间的界面反应限制了其应用。搅拌摩擦加工（FSP）被视为一种在较低温度下制备金属基复合材料的有前景的技术。本文采用FSP制备了石墨烯纳米片增强铝基复合材料（GNPs/Al）。深入研究了工艺参数和石墨烯含量对GNPs/Al的相应影响。结果表明，塑性应变、热输入和石墨烯含量是关键影响因素。较大程度的塑性应变可通过增加搅拌道次以及搅拌速度与焊接速度之比来增强石墨烯的分散，从而提高GNPs/Al的强度。低热输入会限制石墨烯在基体中的塑性流动，而过高的热输入会促进界面反应并导致形成更脆的相AlC。这主要与搅拌速度和焊接速度有关。高石墨烯含量可通过细化晶粒尺寸、提高载荷传递能力以及作为析出物阻止位错运动来提高材料强度。这些发现为含石墨烯增强的先进铝合金的开发做出了贡献，在工业中具有更广阔的应用潜力。
