超声喷丸FGH97粉末高温合金表面粗糙度试验与数值分析

Surface Roughness Numerical and Test Evaluation of FGH97 Powder Superalloy by Ultrasonic Shot Peening

目的为了探究超声喷丸对FGH97粉末高温合金表面粗糙度的影响规律,验证超声喷丸有限元粗糙度预测模型的可行性。方法在0.13 A与0.18 A的喷丸强度下进行超声喷丸表征试验及数值模拟分析,研究了FGH97粉末高温镍基合金超声喷丸后的粗糙度变化。建立了超声喷丸三维有限元模型(腔室几何模型、批量弹丸模型、振动系统、Johnson-Cook材料本构模型),两种喷丸强度下沿试样横向与纵向的Ra、R_z试验值测量数目均为25个,计算了两种喷丸强度下试样横纵向粗糙度均值的相对标准偏差。结果 0.18 A超声喷丸试验横纵向整体粗糙度均值Ra、Rz值分别为0.96μm、4.25μm,0.18 A超声喷丸数值仿真横纵向粗糙度Ra、Rz均值分别为1.02μm、4.3μm,横纵向粗糙度仿真值与试验数据最终评估值的差异小于10%,证实了FGH97粉末高温合金超声喷丸数值仿真预测的有效性,得出10个极值的取样测量数目更能准确反映出超声喷丸后试样表面粗糙度情况。结论喷丸强度的增加降低了粗糙度值分布的离散度,同时,相对标准偏差的差异性结果证明,在超声喷丸强化表面粗糙度分析前,对试样前处理状态进行测量分析是必要的。

In order to explore the influence of ultrasonic shot peening on the surface roughness of FGH97 powder nickel-based alloy,and verify the feasibility of the finite element roughness prediction model of ultrasonic shot peening,characterization test and numerical simulation analysis are carried out under the shot peening intensities of 0.13 A and 0.18 A,respectively.The roughness variation of FGH97 powder nickel-based alloy after ultrasonic shot peening is studied,and the three-dimensional ultrasonic shot peening finite element model(chamber geometric model,batch spheres model,vibration system,Johnson-Cook material constitutive model)is established.Under the two shot peening intensities,the number of measurement of Ra and Rz test values along the horizon and vertical directions of the sample are 25,respectively,and the relative standard deviation of the average value of the horizon and vertical roughness of the sample are calculated.The results show that the mean Ra and Rz values of the overall roughness are 0.96μm and 4.25μm,respectively.Based on the numerical simulation prediction analysis of 0.18 A ultrasonic peening process parameters,it is obtained that the average values of the horizon and vertical roughness Ra and Rz are 1.02μm and 4.3μm,respectively.The difference between the horizon and vertical roughness values and the final evaluation value of the test data is less than 10%,which confirms the validity of FGH97 powder nickel-based alloy ultrasonic shot peening numerical simulation prediction,and it is concluded that the number of 10 extreme sampling measurements can more accurately reflect the surface roughness of the sample after ultrasonic shot peening.The increase in shot peening intensity reduces the dispersion of the distribution of the roughness value.At the same time,the difference in relative standard deviation proves that the measurement and analysis of the pretreatment state of the sample before ultrasonic shot peening is necessary.