镍基单晶高温合金磨削变质层工艺试验研究

为探究镍基单晶高温合金的磨削变质层工艺特性，采用单因素试验的方法，研究不同磨削参数及冷却条件对磨削变质层厚度的影响规律.结果表明，在镍基单晶高温合金DD5的磨削表面及亚表面存在一定厚度的磨削变质层.磨削变质层中的塑性变形层内γ相和γ′相发生剧烈扭曲变形且磨削变质层的硬度大于基体.不同磨削参数及冷却条件对磨削变质层厚度产生不同影响，随着砂轮线速度、磨削深度、工件进给速度的增加，磨削变质层厚度的变化分别表现为先减小后增大、不断增大、先增大后减小；在试验参数范围内，微量润滑(MQL)作为冷却条件可以降低相应的磨削变质层厚度，最多达到3.5μm.

Experimental Study on the Grinding Metamorphic Layer of Nickel-based Single Crystal Superalloy

In order to explore the processing property of grinding metamorphic layers of nickel-based single crystal superalloy， a single-factorial plain grinding experiment was conducted to investigate the effect of different grinding parameters and cooling conditions on the thickness of grinding metamorphic layers. The results showed that the grinding metamorphic layer with certain thickness appears on the grinding surface and subsurface of nickel-based single crystal superalloy DD5. The γ phase and γ′ phase in the plastic deformation layer of the metamorphic layer are distorted severely， and the hardness of the grinding metamorphic layer is greater than that of the matrix. The grinding metamorphic layer thickness varies with the grinding parameters and cooling conditions. With the increase of grinding wheel tangential velocity， the metamorphic layer thickness first decreases， and then increases; with the increase of grinding depth， the metamorphic layer thickness increases continuously; with the increase of workpiece feed velocity， the metamorphic layer thickness first increases， and then decreases. Within the range of experiment parameters， the minimum quantity lubrication (MQL) cooling condition can reduce the corresponding grinding metamorphic layer thickness， which can be reduced by up to 3.5μm.