Zhang Jiajia, Qian Mingfang, Jia Zhenggang, Zhang Xuexi, Li Aibin, Wang Guisong, Geng Lin
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Materials (Basel). 2024 May 20;17(10):2460. doi: 10.3390/ma17102460.
The distribution of reinforcements and interfacial bonding state with the metal matrix are crucial factors in achieving excellent comprehensive mechanical properties for aluminum (Al) matrix composites. Normally, after heat treatment, graphene nanosheets (GNSs)/Al composites experience a significant loss of strength. Here, better performance of GNS/Al was explored with a hybrid strategy by introducing 0.9 vol.% silicon carbide nanoparticles (SiCnp) into the composite. Pre-ball milling of Al powders and 0.9 vol.% SiCnp gained Al flakes that provided a large dispersion area for 3.0 vol.% GNS during the shift speed ball milling process, leading to uniformly dispersed GNS for both as-sintered and as-extruded (0.9 vol.% SiCnp + 3.0 vol.% GNS)/Al. High-temperature heat treatment at 600 °C for 60 min was performed on the as-extruded composite, giving rise to intragranular distribution of SiCnp due to recrystallization and grain growth of the Al matrix. Meanwhile, nanoscale AlC, which can act as an additional reinforcing nanoparticle, was generated because of an appropriate interfacial reaction between GNS and Al. The intragranular distribution of both nanoparticles improves the Al matrix continuity of composites and plays a key role in ensuring the plasticity of composites. As a result, the work hardening ability of the heat-treated hybrid (0.9 vol.% SiCnp + 3.0 vol.% GNS)/Al composite was well improved, and the tensile elongation increased by 42.7% with little loss of the strength. The present work provides a new strategy in achieving coordination on strength-plasticity of Al matrix composites.
增强体的分布以及与金属基体的界面结合状态是实现铝基复合材料优异综合力学性能的关键因素。通常，经过热处理后，石墨烯纳米片（GNSs）/铝复合材料的强度会显著损失。在此，通过向复合材料中引入0.9体积%的碳化硅纳米颗粒（SiCnp），采用混合策略探索了GNS/铝更好的性能。对铝粉和0.9体积%的SiCnp进行预球磨得到铝薄片，在变速球磨过程中为3.0体积%的GNS提供了较大的分散面积，从而使烧结态和挤压态（0.9体积% SiCnp + 3.0体积% GNS）/铝中的GNS均匀分散。对挤压态复合材料在600℃下进行60分钟的高温热处理，由于铝基体的再结晶和晶粒长大，导致SiCnp呈晶内分布。同时，由于GNS与铝之间适当的界面反应，生成了可作为额外增强纳米颗粒的纳米级AlC。两种纳米颗粒的晶内分布改善了复合材料中铝基体的连续性，并在确保复合材料的塑性方面起关键作用。结果，热处理后的混合（0.9体积% SiCnp + 3.0体积% GNS）/铝复合材料的加工硬化能力得到了很好的提高，拉伸伸长率提高了42.7%，而强度几乎没有损失。本工作为实现铝基复合材料强度与塑性的协调提供了一种新策略。
