高级检索

热喷涂TiB2-Ni复合涂层组织结构和力学性能

Microstructure and mechanical properties of TiB2-Ni composite coating

  • 摘要: 采用团聚烧结方法制备TiB2-Ni复合粉末喂料,并采用大气等离子喷涂和高速火焰喷涂两种喷涂方法制备了TiB2-Ni涂层,比较分析了两种涂层的显微组织、物相组成、孔隙率、硬度和断裂韧性.结果表明,与等离子喷涂相比,高速火焰喷涂制备的TiB2-Ni涂层具有更高的致密度,TiB2含量,硬度和断裂韧性.两种涂层中TiB2都没有发生明显的脱硼,氧化,但等离子喷涂过程中TiB2向金属相中发生了溶解生成了大量脆性Ni20Ti3B6相,并降低了涂层中TiB2的含量,这是涂层硬度和断裂韧性相对较低的主要原因.

     

    Abstract: The TiB2-Ni composite powder feedstock was fabricated by agglomeration and sintering method. This powder was used to deposit TiB2-Ni coating by two thermal spray technologies, atmospheric plasma spray(APS) and high velocity oxygen fuel spray(HVOF). The microstructure, phase constitution, porosity, hardness and fracture toughness of two sprayed TiB2-Ni coatings were compared and analyzed. The results showed that the HVOF sprayed TiB2-Ni coating had more compact structure, larger TiB2 content, higher hardness and better fracture toughness than the APSed coating. The TiB2 in two coatings had no obviously deboronization and oxidation. However, the TiB2 in APS process was dissolved in metallic phase to form a large number of brittle Ni20Ti3B6 phases. This dissolution reaction reduced the TiB2 content in coating and it was the main reason for the lower hardness and worse fracture toughness of APSed TiB2-Ni coating.

     

/

返回文章
返回