面向高速切削的镍白铜材料本构模型和摩擦模型及其构建方法

Cupronickel is a strategic material used in the manufacture of the aircraft carrier, and high-speed cutting (HSC) is a prior selection of the removal machining of cupronickel. Many new deformation and friction questions will be caused by the high cutting speed of cupronickel, such as ultra-high strain rate, high strain and the changing trends of each deformation and friction effect. The traditional material constitutive model and friction model can’t meet the description of deformation and friction characteristics of HSC again. Furthermore, the corresponding construction methods of the models are also necessary to be solved urgently. In this project, a high-speed orthogonal cutting method (HS-OCM), aided by split Hopkinson pressure bar (SHPB) experiments which will emphatically consider the deformation temperature of the impacted specimen and the blank area existed between SHPB and HS-OCM, will be employed to research the deformation effects of HSC of cupronickel and obtain its material constitutive model. Then a general constitutive model for plastic metals will be proposed. The single factor experimental method of high-speed, high-temperature and changed load will be used to acquire each factor effect of the inner and external friction of cupronickel, and obtain the inner and external friction model for HSC of cupronickel. The obtained models of cupronickel have important scientific significance and academic value because it can reveal the mechanism of the deformation and friction behaviors of HSC of cupronickel and can also support the building of physical simulation model for HSC of cupronickel.

镍白铜是航母制造中的重要战略用材，高速切削是其除料加工的优先选择。镍白铜高的切削速度引发了超高应变率、高应变、变形和摩擦效应项的趋势拐点变化等新问题，传统的材料本构模型和摩擦模型已不能适应描述镍白铜高速切削的变形和摩擦特性，相应的构建方法也急需解决和完善。本项目拟采用高速直角切削方法(HS-OCM)，辅以分离式Hopkinson压杆（SHPB）实验，考虑冲击试件变形温度问题以及SHPB和HS-OCM之间空白区问题，研究高速切削镍白铜的变形效应规律，获得镍白铜的材料本构模型，并提出适合描述塑性金属高速切削变形特征的通用本构模型；采用高速高温变载荷单因素实验方法，研究镍白铜内外摩擦的各因素效应，获取镍白铜面向高速切削的内外摩擦模型。所得的镍白铜材料和摩擦模型对于揭示其高速切削变形和摩擦机理，以及镍白铜高速切削物理仿真建模具有重要的科学意义和学术价值。

镍白铜是航母制造的重要战略用材，高速切削是其优先加工选择。镍白铜高切削速度引发超高应变率、高应变、变形和摩擦效应项的趋势拐点变化等新问题，传统材料模型和摩擦模型已不能适应新情况，相应构建方法也需解决。因此本项目围绕上述问题展开研究，并拓展研究了切屑形成、表面硬化层、切削区面积和变形区冲压行为。.采用分离式霍普金森杆（SHPB）方法，考虑试件变形温度，研究镍白铜材料的应变、应变率和热效应，完善SHPB方法和修正JC模型；提出基于滑移距的高速直角切削理论模型和实验方法(HS-OCM)，解决常规直角切削方法受许可速度的限制问题；考虑SHPB和HS-OCM间空白区问题，建立两种方法所得材料变形特征的内在联系，获得高速切削变形特征效应曲线；提出面向高速切削的材料本构模型，验证表明能够更准确地描述高速切削剪切变形特性。.根据高速切削摩擦的特点，提出基于因素效应的高速切削刀-屑摩擦模型；发明液压式和固液气减振式高速摩擦实验装置，结合SRV摩擦装置，研究工件和刀具材料配副下的高速高温变载荷摩擦特性，讨论其摩擦机理；分解摩擦特性曲线，解析出速度效应、热效应和载荷效应曲线，获得镍白铜高速切削摩擦模型，验证表明能够准确描述高速切削刀-屑摩擦特性。.对所得的镍白铜材料本构模型进行仿真验证，分为二维直角切削和三维车削，结果表明DP模型较JC模型具有更准确的描述效果，同时验证所得镍白铜材料本构模型的有效性；对所构建的材料本构模型和摩擦模型进行综合验证，结果表明，所构建的模型可将主切削力和切削温度的最大仿真误差降为11.6%和11.2%。.在高速情况下，镍白铜切屑形态趋向于锯齿状；高速切削会提高工件表面硬化，即可提高镍白铜零件的海洋耐腐蚀性；提出了高速切削变形区面积的理论模型，研究表明高切削速度会提高切削区面积；在阐述锯齿状切屑形成过程中，发现了压缩变形明显存在第一变形区，提出了压缩变形特征的理论模型，结合直角切削实验，获得压缩变形特征数据和变化规律。