溶胶-凝胶法制备准晶颗粒涂层及其表征

Preparation and Characterization of the Coating on Al-Ni-Co Quasicrystalline Particles by Sol-Gel Method

采用常规铸造法和球磨法制备得到单相Al-Ni-Co十次准晶颗粒,并采用溶胶-凝胶法在准晶颗粒表面成功的添加了涂层。分别采用XRD、SEM、FE-SEM和EDS分析了干凝胶以及添加涂层后准晶颗粒的微观组织、形态以及界面情况。实验结果表明,制备得到的干凝胶为非晶态的勃姆石,经高温煅烧后它转化为α-+δ-+θ-Al2O3晶体相。而添加涂层后的准晶颗粒经高温煅烧后,其相组成为DQC+α-+β-+θ-Al2O3,准晶仍然保持较高的热稳定性。FE-SEM分析结果表明,涂层与颗粒的界面结合特性良好,涂层的厚度约为0.71～0.91μm,均匀分布于颗粒表面。

Single Al-Ni-Co decagonal quasicrystal particles were prepared by the combination use of conventional casting and ball milling. The coated Al-Ni-Co quasicrystalline particles were prepared by sol-gel processing. The microstructures, morphologies and interfacial characteristics of dry gel and the coated Al-Ni-Co quasicrystallie particles were investigated in detail through XRD, SEM, FE- SEM, and EDS methods. The dry gel consists of amorphous AIOOH and α-, δ-, and θ-Al2O3 before and after calcination. While the coated quasicrystalline particles consist of AIOOH ＋ DQC and DQC ＋ α-＋ β-＋ θ-Al2O3 before and after calcination. The quasicrystal remains high thermodynamic stability. FE-SEM observations indicate that it shows good bonding behavior between quasicrystalline particles and the Al2O3 coating, and Al2O3 coating are uniformly and continuously deposited on the surfaces of DQC particles, with an average thickness of about 0.71-0.91 μm.