K403镍基合金渗铝层微裂纹与扭转应力关系

Relationship between micro-crack and torsional stress of K403 Ni-base alloy aluminized layer

研究了扭转应变下K403镍基合金渗铝层厚度与渗铝层微裂纹的关系。应用Auto CAD建立试样及夹具模型,采用Jmat Pro软件计算渗铝层铝含量为25%（质量分数）的物理性能和力学性能,通过DEFORM软件进行有限元扭转模拟,研究了渗铝层应力变化规律。采用粉末包埋法在K403镍基合金表面制备渗铝层,渗铝试样通过扭转、着色,观察渗层表面形貌。结果表明：在扭转角3°和5°,当渗铝层厚度在20~30μm,随着渗铝层厚度的增加,K403镍基合金渗铝层等效应力反而减小。渗铝层出现的微裂纹主要集中在试样中间区域。随着扭转角的增大,微裂纹分布将由中间向四周扩展。

The relationship between the thickness and the micro-cracks of aluminized layer of K403 nickel-based alloy under torsional strain was studied. The physical and mechanical properties of aluminized layer with aluminum content of 25%（ mass fraction） were calculated by Jmat Pro software. The finite element torsion simulation was carried out by using DEFORM software,and the stress variation of aluminized layer was studied. The aluminized coating was prepared on the surface of K403 nickel base alloy by powder packing aluminizing method. The surface morphologies of the aluminized layer was observed after torsion and coloring. The results show that when the thickness of aluminized layer is 20-30 μm and the angle of torsion is 3° and 5°,the equivalent stress in the aluminized layer reduces with increase of the thickness of the aluminized layer. The micro-cracks in the aluminized layer are mainly formed at the middle area of the sample. With increase of the twist angle,the distribution of the micro-crack extends from the center to the periphery.