论文部分内容阅读
采用超音速火焰喷涂技术在45#钢基体表面制备纳米Ni60-TiB_2复合涂层,研究了纳米和常规微米Ni60-TiB_2复合涂层在静态大气环境下600℃的循环氧化行为。结果表明:纳米Ni60-TiB_2涂层具有晶粒纳米化和微观组织均匀化的特点,其氧化膜由完整连续SiO_2膜构成,在其上均匀地分布着细小的TiO_2颗粒和B_2O_3膜。纳米涂层和微米涂层的循环氧化都为扩散控制机制,但是在纳米涂层表面生成了连续致密的SiO_2膜。晶粒纳米化降低了涂层内应力,提高了膜基结合力,保证了氧化膜的完整性,因此使Ni60-TiB_2复合涂层具有更优的抗氧化性能。
Nanosized Ni60-TiB_2 composite coatings were prepared on the surface of 45 # steel by supersonic flame spraying. The cyclic oxidation behavior of nanocrystalline and conventional Ni60-TiB_2 composite coatings at 600 ℃ under static atmosphere was studied. The results show that nano-sized Ni60-TiB_2 coating has the characteristics of nanocrystallization and homogenization of microstructure. The oxide film consists of a continuous film of SiO_2, on which fine TiO 2 particles and B 2 O 3 film are uniformly distributed. The cyclic oxidation of nano-coating and micro-coating are all diffusion control mechanisms, but continuous dense SiO 2 film was formed on the surface of nano-coating. Nanocrystallization reduces the internal stress of the coating, improves the bonding strength of the film, and ensures the integrity of the oxide film. Therefore, the Ni60-TiB_2 composite coating has better oxidation resistance.