材料大去除率铣削下航空钛合金回弹诱振机理及其控制策略

In order to solve such problems as extremly vibration, intensive wear of cutting tool and poor tool life resulted from spring-back in milling process of titanium alloy with high material removal rate, to break up the restriction of tool life during cutting process with large material removal rate, a vibration control theory of titanium alloy milling is proposed. In this project, a innovative time-delay dynamic model of spring-back of titanium alloy is approached to summerized the springback deformation trends under combination of milling parameters by the signals processing method(Independent Component Analysis, ICA) of milling force and tool vibration and workpiece vibration. In analyzing process, this vibration theory will reveal those internal vibration mechanism of titanium alloy cutting system caused by spring-back in milling titanium alloy with large material removal rate combined with the finite element analysis method. For mlling titanium alloy with large material removal rate, new structure tools with better vibration control abilities are developed and optimal milling paramenters combinations are approximated, which can extremly decrease the virbration amplitude of the whole cutting system, improve the machining quality and tool life, consequently promote the titanium alloy milling with high speed and efficency.

为解决钛合金大去除率下因回弹变形导致的剧烈振动、刀具后刀面急剧磨损、耐用度显著下降等问题，突破因刀具寿命制约钛合金高速铣削的瓶颈，提出抑制钛合金回弹变形引起振动的消减控制理论。采集钛合金大材料去除率下工件振动位移、铣削力和铣刀振动位移信号，创新性地利用独立变量分析（ICA）信号处理方法，探寻钛合金大去除率工艺条件下的回弹变形规律，构建钛合金回弹变形下的切削系统时滞动力学模型，结合有限元分析揭示钛合金大去除率下因大应变回弹变形引起切削系统振动的内在机制，创建基于ICA信号处理的钛合金大应变回弹诱振分析理论体系；研究抑制回弹诱振的削减机制和策略，优化立铣刀刀具结构，开发具有良好抑振性能的钛合金大去除率铣削加工刀具，优选抑振性能明显的工艺参数，全面降低切削的系统振动能量、提高加工质量、延长刀具寿命，达到提升钛合金高速高效加工的目的。

为解决钛合金大去除率下因回弹变形导致的剧烈振动、刀具后刀面急剧磨损、耐用度显著下降等问题，突破因刀具寿命制约钛合金高速铣削的瓶颈，提出抑制钛合金回弹变形引起振动的消减控制理论。首先根据接触力学和摩擦学原理，计算了钛合金压力和回弹之间的关系，为已加工表面的回弹量计算提供理论基础；分析了温度对弹性模量的影响规律，并利用胡克定律推出已加工表面回弹的推导公式，以主轴转动速度、径向切宽、轴向切深、每齿进给、铣刀前角、后角为六个影响因素，设计六因素五水平正交表，利用有限元仿真软件AdvantEdge进行二维铣削仿真，得到六个因素对最高切削温度、y向应力及已加工表面回弹量的影响规律，以切削温度、已加工表面回弹量为优化目标，选取最佳的刀具结构参数和加工工艺参数，为后继试验设计提供理论指导；根据仿真选取的最佳刀具结构和工艺参数，利用频谱分析、小波分析，并通过试验设计并分析了切削振动对钛合金切削质量的影响，设计了刀具磨损对切削质量的影响，从而迫切地提出合理的切削参数和利用减振铣刀如变齿距铣刀进行钛合金铣削；根据切削力频谱均匀性原则分析了变齿距铣刀的减振机理，最后进行了普通铣刀和变齿距减振铣刀进行钛合金薄壁件铣刀试验，从铣削力和刀具振动位移上分析了变齿距铣刀进行钛合金铣削的减振特性，并利用小波分析分析并验证了变齿距铣刀的频谱分布特点，间接验证了变齿距铣刀的减振特性。该研究为提高钛合金高效铣削提供了理论指导意义。