磨粒高速冲击陶瓷的响应和磨料水射流车削工艺参数优化研究

发布时间：2018-03-06 11:34

  本文选题：磨料水射流车削　切入点：高速冲击响应　出处：《山东大学》2016年博士论文　论文类型：学位论文

【摘要】：针对现有磨料水射流车削研究中存在诸如硬脆材料车削性能和车削机理研究较少、车削性能模型不具有通用性、车削工艺参数多目标优化模型欠缺等问题,本文主要研究了磨粒高速冲击陶瓷的响应和磨料水射流车削工艺参数优化。实验研究了磨料水射流的车削性能,揭示了车削工艺参数对车削性能的影响。研究了磨料粒子高速冲击氧化铝陶瓷的响应,揭示了材料冲击过程的微观机理。建立了基于有限元法的磨料水射流车削陶瓷的切除深度通用模型,研究了车削工艺参数及其交互作用对切除深度和表面粗糙度的影响,解决了径向模式车削中难以控制切除深度的难题。建立了磨料水射流车削陶瓷的工艺参数优化模型。这些研究成果将为径向模式磨料水射流车削陶瓷等硬脆材料提供重要的理论基础和技术保障。实验研究了磨料水射流车削氧化铝陶瓷的主要工艺参数对材料切除深度和材料去除率的影响。结果表明,喷嘴横向移动速度和水射流压强对切除深度和材料去除率的影响较大,靶距和工件表面线速度对切除深度和材料去除率的影响较小；研究了磨料水射流车削氧化铝陶瓷的材料去除机理。结果表明,以较小的喷嘴倾斜角度车削时,陶瓷的主要去除机理是塑性剪切,以较大的喷嘴倾斜角度来车削时,陶瓷的主要去除机理是脆性断裂。研究了磨料粒子高速冲击氧化铝陶瓷时的冲击响应。建立了三维单颗磨料粒子冲击氧化铝陶瓷的有限元模型。基于有限元模型获得了磨料粒子的冲击动能效率。结果表明,磨料粒子的冲击动能效率随着冲击速度、喷嘴倾斜角度和磨粒尺寸的增加而增大,磨料粒子的冲击动能效率越大,表明磨料粒子的冲击能力越强；通过有限元模型分析了不同冲击速度和不同喷嘴倾斜角度下,靶材在不同时刻的应力分布。冲击后的靶材表面单元受压应力,非冲击表面单元受拉应力；研究了不同形状磨料粒子高速冲击氧化铝陶瓷的响应。结果表明,球形和圆锥形磨料粒子的冲击动能效率较高,冲蚀凹坑体积和深度较大。立方体形和圆柱体形磨料粒子的冲击动能效率较低,冲蚀凹坑体积和深度较小。磨料粒子形状对冲蚀凹坑体积、凹坑深度和冲击动能效率三者的影响趋势一致；建立的三维磨料粒子高速冲击氧化铝陶瓷的有限元模型能较好地预测冲蚀凹坑体积和冲蚀凹坑深度。结果表明,不同冲击速度、不同喷嘴倾斜角度和不同磨料尺寸下的冲蚀凹坑体积和冲蚀凹坑深度的预测值与实验值基本吻合。研究了单颗磨料粒子高速冲击陶瓷的微观去除机理。结果表明,其主要去除机理是裂纹分叉和聚合以及微孔洞；研究了不同排布的四颗磨料粒子高速冲击陶瓷的冲击响应。结果表明,四颗磨料粒子高速冲击氧化铝陶瓷时,磨料粒子产生的应力波叠加和耦合作用是陶瓷表面材料大范围去除的主要机理；建立了磨料水射流车削氧化铝陶瓷的切除深度通用模型。切除深度预测值与实验值具有较好的一致性,两者之间的平均相对误差小于15%。利用响应曲面法研究了磨料水射流车削氧化铝陶瓷的工艺参数建模和优化。研究了磨料水射流工艺参数之间的交互作用对切除深度和表面粗糙度的影响。结果表明,在较小的喷嘴横向移动速度和较大的水射流压强条件、较小的喷嘴横向移动速度和较大的磨料流量条件,或较小的喷嘴横向移动速度和较大的靶距条件时,切除深度最大。由于二次方效应,当水射流压强和磨料流量都取中间值时,表面粗糙度最小。喷嘴横向移动速度和磨料流量之间的交互作用对切除深度和表面粗糙度的影响较大；利用期望度函数响应曲面法研究了获得期望切除深度和表面粗糙度时的工艺参数优化。结果表明,在第一套准则优化的工艺参数下获得的最大切除深度为480μm,表面粗糙度为10.3μm。在第二套准则优化的工艺参数下获得的最大切除深度为390μm,最小表面粗糙度为5.3μm。实验验证了工艺参数优化结果的有效性。
[Abstract]:Aiming at the problems such as hard and brittle materials turning performance and cutting mechanism of abrasive water jet cutting of the existing research, turning performance model is not universal, a multi-objective optimization model of turning process parameters such as lack of problem, this paper mainly studies the impact of high speed abrasive ceramic ring and abrasive water jet cutting process parameters were experimentally investigated. The machinability of abrasive water jet, reveals the influence of process parameters on the performance of the lathe turning. The response of abrasive particles in high speed impact of alumina ceramic materials, the micro mechanism of impact process was revealed. A general model of resection depth of the finite element method of abrasive water jet based on ceramic turning, turning process parameters and their interactions the ablation depth and surface roughness effects, and solve the difficult problem of the control of cutting depth. The radial mode in turning abrasive water Parameter optimization model of jet turning ceramic. These research results will provide technical support and theoretical basis for hard brittle materials with abrasive water jet cutting ceramic radial mode. The main parameters influencing experimental study on abrasive water jet cutting of alumina ceramic material removal depth and material removal rate. The results show that the influence of lateral nozzle the moving speed and water jet pressure on the cutting depth and the material removal rate is larger, smaller effects of target distance and surface line speed on the cutting depth and the material removal rate; removal mechanism of abrasive water jet cutting of alumina ceramic materials. The results show that the nozzle with smaller inclination angle when turning, the main mechanism of the removal of ceramic is the plastic shear, to turning to larger nozzle inclination angle, the main mechanism of the removal of ceramic is brittle fracture of high speed abrasive particles. The impact of the shock response of alumina ceramics. To establish a three-dimensional finite element of single abrasive particle impact of alumina ceramic model. Based on the finite element model of the impact energy efficiency of abrasive particles. The results show that the impact energy efficiency of abrasive particles with increasing impact velocity, nozzle inclination angle and the grain size increases, the impact kinetic energy the greater the efficiency of abrasive particles, abrasive particles that impact ability is stronger; the finite element model to analyze the impact of different velocity and different nozzle inclination angle, the stress distribution of the target at different time. The stress surface of a target unit compression after impact and non impact surface unit tensile stress on the response of different; the shape of abrasive particles in high speed impact of alumina ceramics. The results show that the impact energy efficiency high spherical and conical abrasive particles, the erosion pit depth and volume larger. The impact energy efficiency and cylindrical shape of abrasive particles is low, erosion pit depth and volume is small. The volume of abrasive particle shape on the erosion pits, pit depth and the influence of the three impact energy efficiency; three-dimensional finite element model of abrasive particles in high-speed impact of alumina ceramics established can better predict the erosion volume and the erosion pits pit depth. The results show that different impact velocity, different nozzle inclination angle and different size abrasive erosion pit volume and erosion pit depth values coincide with the experimental values. The microscopic mechanism of single abrasive particle impacting ceramic removal. The results showed that the main removal mechanism is crack bifurcation and polymerization and microporous four abrasive particle hole; high speed impact ceramic impact response of different arrangement. The results showed that four of abrasive particles at high speed On alumina ceramic, abrasive particles produced by stress wave superposition and coupling effect is the main mechanism of material removal of a wide range of ceramic surface; a general model of abrasive water jet depth for turning alumina ceramics. Resection depth prediction value has a good agreement with the experimental data, the average relative error between them is less than 15%. by modeling and optimization of process parameters of abrasive water jet cutting of alumina ceramics by response surface methodology. Studies the interaction between abrasive water jet parameters on ablation depth and surface roughness effects. The results show that the nozzle traverse speed of smaller and larger water jet pressure conditions, the smaller the nozzle moving speed and lateral the larger or smaller abrasive flow conditions, the nozzle moving speed of horizontal and larger target distance conditions, the maximum depth of resection due to two side effects. When the water jet pressure, abrasive flow rate and has the intermediate value, minimum surface roughness. Between the nozzle traverse speed and abrasive flow interaction on the ablation depth and surface roughness of the larger; with the expectation degree function of the desired resection depth and surface roughness parameter optimization by response surface method. The results show that the gain in the first set of criteria for the optimization of process parameters of the maximum ablation depth was 480 m, the surface roughness of 10.3 M. in the second set of criteria for the optimization of process parameters of the maximum ablation depth was 390 m, the surface roughness of 5.3 M. experiments to validate the optimization results the process parameters.

【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG664;TQ174.6
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本文编号：1574668