B_4C/Al-Al层状复合材料的微观组织与力学性能

Microstructure and mechanical properties of B_4C/Al-Al layered composites

以6061Al合金板为包覆材料,以B4C/Al材料作为中间层,采用粉末冶金法制备三明治结构的B4C/Al-Al层状复合板,进一步轧制成不同厚度的板材。对复合板的微观形貌与结构进行观察和分析,测试材料的抗拉强度和硬度,分析断裂机理。结果表明:B4C/Al-Al层状复合板的Al合金层和B4C/Al层之间界面结合良好,在B4C/Al层中B4C颗粒均匀分布在Al合金基体中;复合材料的硬度呈"馒头峰"分布,中间层的硬度大于包覆层的硬度;随板材轧制厚度减小,复合材料的抗拉强度提高,最大抗拉强度达205 MPa,与轧向呈0°,45°和90°这3个方向的抗拉强度相差不大,拉伸过程中的温升差约为2℃;B4C颗粒的加入对Al合金基体起到强化作用,断裂过程中的失效形式主要为颗粒/基体界面脱粘和铝合金的撕裂。

Using 6061 Al as cladding material and B4C/Al composite as interlayer, B4C/Al-Al layered composite was fabricated by power metallurgy and followed by hot rolling with different thicknesses. The SEM morphology and microstructure of the fabricated composites were observed and analyzed, the tensile strength and hardness were tested, fracture mechanism was also explored. The results show that the interface of B4C/Al and Al layer is well combined. And the distribution of B4 C particles in the 6061 Al alloy matrix is almost homogeneous. The hardness of the composite presentes the bread peak distribution, the interlayer has higher hardness than the surface layer. The tensile strength increases with the increase of thickness. The maximum tensile strength is 205 MPa and the rolling direction（0°, 45° and 90°） has little effect on the tensile strength. A temperature fluctuant range of 2 ℃ in tensile test is found. The B4 C particles plays a reinforce role in the composites and the microstructure damage is dominated by interface debonding and Al tearing.