纳米Fe-Al/Cr_3C_2复合涂层的制备及性能研究

目的制备纳米Fe-Al/Cr_3C_2复合涂层并对比分析结合强度、显微硬度、孔隙率,为利用热喷涂技术治理易损部件提供有效手段。方法运用自主研发的造粒系统,成功对高活性的纳米Fe-Al/Cr_3C_2复合喷涂粉体实施团聚造粒。使用高速火焰喷涂方法,在结构材料表面制备出了纳米Fe-Al/Cr_3C_2复合涂层。测试了纳米Fe-Al/Cr_3C_2复合涂层的基本性能,包括结合强度、显微硬度、孔隙率。结果纳米Fe-Al/Cr_3C_2复合喷涂材料的粒径由原始的50 nm团聚到最终的114~178μm,团聚后的纳米颗粒呈圆形或椭圆形,各成分比例保持原始比例,团聚颗粒内部仍然保持纳米粉体状态。纳米Fe-Al/Cr_3C_2表面及截面元素分布均匀、致密,纳米涂层的孔隙率、硬度和结合强度分别是微米涂层的0.25倍、1.39倍和2.43倍。结论团聚后的纳米Fe-Al/Cr_3C_2颗粒满足热喷涂材料的相关要求,纳米Fe-Al/Cr_3C_2比微米涂层具有更精细的涂层结构和更优异的基本性能。

Fabrication and Properties of Nano Fe-Al/Cr3C2 Composite Coatings

The work aims to fabricate nano Fe-Al/Cr3C2 composite coatings, compare and analyze adhesion strength, microhardness and porosity, so as to provide an effective technical method for treating damageable parts by applying thermal spraying technology. Reunion-granulation was successfully applied to highly active nano Fe-Al/Cr3C2 composite spraying materials by using independently developed reunion-granulation system. Nano-Fe-Al/Cr3C2 composite coatings were made on structural materials in the method of high velocity flame spraying (HVFS). Basic properties of the nano Fe-Al/Cr3C2 composite coatings, including adhesion strength, micro-hardness and porosity were tested. Particle size of Fe-Al/Cr3C2 composite spraying materials changed from 50 nm to 114~178 nm. The nano spraying particles after reunion-granulation were round or oval, proportion of ingredients in granulated particles stayed the same, inner particles of granulated particles kept nanometer state. Elements on the surface and cross section of the nano Fe-Al/Cr3C2 composite coatings were dense and uniformly distributed. The porosity, micro-hardness and adhesion strength of nano Fe-Al/Cr3C2 composite coatings was 0.25 times, 1.39 times and 2.43 times as great as micro Fe-Al/Cr3C2 composite coatings, respectively. Reunion-granulated particles meet relevant requirements of thermal spraying materials completely. Compared with micro Fe-Al/Cr3C2 composite coatings, nano coatings have finer coating structure and superior basic properties.