GH4169高温合金化学铣切表面粗糙度的影响因素

为了满足生产对GH4169高温合金化学铣切加工表面粗糙度的要求,通过单因素试验研究了化铣液的主要成分和化铣工艺参数对GH4169高温合金表面粗糙度的影响。结果表明:随着化铣液中FeCl3和HNO3浓度的升高,表面粗糙度呈下降趋势;当化铣液温度高于50℃时,表面粗糙度在1.4μm以下;HCl,HF浓度均为200 mL/L时,表面粗糙度最小;添加剂SA和SN能够降低表面粗糙度和消除凹槽;随着化铣液中Ni2+浓度的增加,表面粗糙度也随之变大,当Ni2+浓度大于26.95 g/L时,表面粗糙度达到1.6μm以上,不符合加工要求;最佳化铣工艺为200～250 g/L FeCl3,200 mL/L HF,150 mL/L HNO3,200 mL/L HCl,0.2 g/L添加剂SA,0.5 mL/L添加剂SN,温度53℃,该工艺下化铣的GH4169高温合金表面质量良好,无凹槽、沟蚀,表面光洁,粗糙度小于1.6μm,符合生产要求。

Factors Influencing Surface Roughness of Chemically Milled GH4169 High-Temperature Alloy

In order to meet the requirements of surface roughness in production of chemically milled GH4169 high-temperature alloy,single factor orthogonal tests were conducted to investigate the effects of composition of the chemical milling solution and processing parameter on the surface roughness of GH4169 high-temperature alloy.It was found that the surface roughness declined with increasing concentration of FeCl 3 and HNO 3 in the chemical milling solution.When the temperature was increased above 50 ℃,the surface roughness reached below 1.4 μm.As both the concentrations of HCl and HF were fixed at 200 mL/L,the minimum surface roughness was obtained.Besides,a certain amount of additives SA and SN could reduce the surface roughness and eliminate grooves on chemically milled surfaces.Moreover,the surface roughness increased with increasing concentration of Ni 2+ and surpassed 1.6 μm when Ni 2+ concentration was above 26.95 g/L,making the chemically milled surface unacceptable in production.The optimal composition of the chemical milling bath was suggested as 200~250 g/L FeCl 3,200 mL/L HF,150 mL/L HNO 3,200 mL/L HCl,0.2 g/L additive SA and 0.5 mL/L additive SN,and the optimal temperature was suggested as 53 ℃.Resultant chemically milled surface was smooth,and free of grooves and gully erosion locations,while its surface roughness was less than 1.6 μm,meeting the requirements for production.