γ-TiAl基金属间化合物机床铣削中的切削力预测

Prediction of Cutting Force in Milling Machining ofγ-TiAl-based Intermetallic Compounds

针对γ-TiAl基合金因室温脆性导致其加工较为困难的问题,提出一种采用正交斜变换技术对γ-TiAl基金属间化合物Ti-48Al-2Cr-2Nb铣削加工切削力进行预测的方法。利用正交车削试验测量切屑厚度、切削力和进给力等,计算出剪切应力、剪切角和摩擦角等基本切削参数。采用正交斜变换技术确定铣削加工的切削系数,并利用端面铣削的切削力解析模型对切削力进行仿真。此外,研究了涂层对摩擦因数、剪切应力、剪切角和切削力的影响。在不同的切削条件下,分别通过端面铣削和球头铣削试验对切削力预测结果进行了验证。结果表明:切削力的预测值与实测值吻合较好,验证了力学模型的有效性;对于AlCrN和AlTiN涂层,端面铣削的切削力估计误差分别在20%和13%内;对于AlCrN涂层,球头铣削的切削力估计误差在15%内。

Aiming at the problem thatγ-TiAl-based alloy is difficult to process because of its brittleness at room temperature,a method to predict the cutting force in the milling machining ofγ-TiAl-based intermetallic compound Ti-48Al-2Cr-2Nb by orthogonal oblique transformation was proposed.The basic cutting parameters such as shear stress,shear angle and friction angle were calculated by using the measurement results of chip thickness,cutting force and feed force in orthogonal turning test.The orthogonal oblique transformation technology was used to determine the milling coefficient,and the analytical model of cutting force for face milling was used to simulate the cutting force.In addition,the effects of coating on friction coefficient,shear stress,shear angle and cutting force were studied.Under different cutting conditions,the cutting force prediction results were verified by face milling and ball milling experiments.The results show that the predicted value of cutting force is in good agreement with the measured value,which verifies the validity of the mechanical model;for AlCrN and AlTiN coatings,the estimation error of cutting force in face milling is in the range of 20%and 13%respectively;for AlCrN coating,the estimation error of cutting force in ball milling is within the range of 15%.