物理法/化学法退除NiCoCrAlYHf涂层对DD6合金表面组织结构的影响

Effect of physical/chemical removal of NiCoCrAlYHf coatings on the surface organisation of DD6 alloy

摘要:

本文采用真空电弧镀工艺在第二代镍基DD6单晶高温合金表面沉积了NiCoCrAlYHf(HY5)涂层,分别采用物理吹砂法与化学溶液浸泡法去除表面涂层,对比研究二者对涂层的去除效果及对基体合金影响程度。结果表明：涂覆的涂层厚度约20μm,主要由γ’及β相组成；经物理法或化学法处理后,基体表面无涂层残留,原始涂层均被完全去除。在物理法吹砂颗粒的切削作用下,基体合金表面宏观上呈现凹凸形貌,微观上沿<110>取向变形产生形变层；物理法破坏了基体合金表面完整性,对基体损伤较大。化学法处理仅在局部区域产生γ’相损伤层,对基体损伤较小。

Abstract:

In this paper, NiCoCrAlYHf (HY5) coating was deposited on the surface of the second-generation nickel-based DD6 single-crystal high-temperature alloy by vacuum arc plating process, and the surface coating was removed by physical blowing sand method and chemical solution immersion method, respectively, for a comparative study of the effect of removal of the coating by the two and the degree of influence on the matrix alloy. The results show that: the thickness of the coating is about 20 μm, which is mainly composed of γ" and β phases; no coating remains on the surface of the substrate after treatment by the physical method or chemical method, and the original coatings are completely removed. Under the cutting action of the sand blowing particles in the physical method, the surface of the matrix alloy presents a concave-convex morphology on the macro level, and the deformation layer is generated by the deformation along the <110> orientation on the micro level; the physical method destroys the integrity of the surface of the matrix alloy, which is more damaging to the matrix. The chemical treatment only produces a γ" phase damage layer in the local area, which is less damaging to the substrate.