车削工艺参数对铝合金211Z加工表面质量的影响

【作者】 张蓉蓉；

【导师】 汪羿；

【作者基本信息】 贵州大学 ， 机械制造及其自动化， 2016， 硕士

【摘要】 耐热高强韧铝合金211Z是近年来我国在新型铝合金材料研发方面取得的一项的重大突破,该材料的研制成功解决了目前高强度铸造铝合金存在的强度不足、配方成本高的问题,是目前强度最高、综合力学性能最好的铸造铝合金材料之一,应用前景十分广阔。较强的塑性和变形能力也使得该材料的切削加工具有一定的特殊性。本文围绕铝合金211Z的动态力学性能,车削加工方式,工艺参数对切削加工性和表面质量的影响等,主要展开了以下几个方面的的研究:1.研究了铝合金211Z的动态力学性能,对其进行常温下准静态加载的拉伸试验和不同温度下的动态压缩实验,得出了相应的应力-应变曲线。依据Johnson-Cook模型,在准静态到动态较宽应变率范围内建立了材料的物理本构方程,为铝合金211Z切削加工的计算机模拟、切削加工变形机理分析奠定了基础。2.在UG中建立了刀具的三维几何模型,在Deform-3D中建立了铝合金211Z的车削有限元模型,仿真了切削加工过程,并开展了车削实验进行验证。3.通过计算机模拟和车削实验,研究了切削用量(切削速度、进给量、背吃刀量)及刀具几何参数(前角、主偏角、刃倾角、刀尖圆弧半径)对铝合金211Z切削力、切削温度的影响规律,建立了切削力、切削温度的预测模型,对预测模型进行了拟合度和回归显著性检验并进行了实验验证,结果表明预测模型能很好的反映切削用量与切削力、切削温度之间的关系。4.通过车削实验研究了切削用量及刀尖圆弧半径对已加工表面粗糙度的影响规律,分别以切削用量、刀尖圆弧半径为自变量,建立了铝合金211Z表面粗糙度的预测模型,并对预测模型进行了修正。5.通过计算机模拟和车削实验,研究了切削用量对铝合金211Z已加工表面残余应力的影响规律,并通过有限元仿真研究了前角对已加工表面残余应力的影响规律。更多还原

【Abstract】 Aluminum alloy 211 Z,a new kind aluminum with heat resistant,high strength and toughness,is a great breakthrough in the research of new type aluminum alloy materials in China in recent years,this invention solves the problems existing in the high-strength aluminum that the strength is insufficient and the cost of formula is high. It is one of the best cast aluminum alloy witch with highest strength and the best comprehensive mechanical properties at present,and it has been widely applied in many fields.Strong plastic and deformation ability causes the material processing of the material has a certain particularity. The dynamic mechanical properties of aluminum alloy 211 Z were studied in this paper,the influence of cutting parameters on the machinability and surface quality of aluminum alloy 211 Z around the turning processingwere also studied, and the main work of this paper is as follows:1.The dynamic mechanical properties of aluminum alloy 211 Z were studied.The quasi-static under the normal temperature and dynamic compressive experiments under different temperature of the aluminum alloy 211 Z are tested, and the corresponding stress-strain curve are got.According to the Johnson-Cook model,the physical constitutive equation for material has been established,which describes the character of material changing from quasi-static to dynamic in a wide strain rates range. It lays the foundation for the computer simulation of cutting process and the analysis of mechanism in cutting deformation for the aluminum alloy 211 Z.2.The three-dimensional geometric model of turning tools are established in UG,the finite element model of the cutting process is established based on Deform-3D for the simulation study of turning and turning experiments are carried out.3.The influences of cutting parameters(cutting speed, feed rate, Cutting depth)and tool geometries(rake angle 、tool lead angle 、inclination angle and corner radius) impact on the cutting force and cutting temperature are studied by computer simulation and turning experiment for the aluminum alloy 211 Z,the cutting force andcutting temperature prediction model are established, Moreover the fitting degree test and significance test are conducted on the prediction model and experimental verification is carried out.The results show that the prediction model can well reflect the relationship between the cutting parameters and the cutting force, the cutting temperature.The influences of the cutting parameters and corner radius on machined surface roughness are studied by turning experiments, the surface roughness prediction models are established with cutting parameters, tool radius as independent variables for aluminum alloy 211 Z,and the prediction model was modified.4. The influence of cutting parameters on the residual stress of machined surface was studied by computer simulation and turning experiment for the aluminum alloy211 Z,and the influence of rake angleon the residual stress of machined surface was also studied by computer simulation.更多还原