基于不同冷却方式的α-氧化铝陶瓷线锯切割机理与工艺研究

发布时间：2018-05-13 18:42

  本文选题：氧化铝 + 雾化冷却　； 参考：《江苏科技大学》2015年硕士论文

【摘要】：陶瓷材料是一种经过高温烧结而形成的无机非金属传统材料,在机械、电子、生物方面应用较为久远,而在材料科学高速发展的现代,对于陶瓷的概念已远远超出传统范畴。与其他材料相比,通过对工艺结构精密控制、添加新化学元素的新型陶瓷,具有阻电性好、高温蠕变小、耐磨损、抗腐蚀、高强度、硬度高、多种敏感性等超越传统陶瓷的特点,并且在航空航天、能源、生物、冶金、电子、光学等行业广泛应用。新型陶瓷材料按其功能应用大致可分为三大类:结构陶瓷、功能陶瓷、生物陶瓷。其中氧化铝陶瓷在结构、功能、生物方面均有应用。α-氧化铝陶瓷作为新型陶瓷典型代表,不但用于制作集成电路基片,人体仿生骨骼,工具刀基体材料,而且还用于航空运载火箭耐高温防护,研磨粉体。但由于α-氧化铝陶瓷硬度高、脆性大,是一种典型的硬脆性材料,受限于传统的机械加工方法。为降低切片表面粗糙度,减少表面刮痕,损伤,变质层,本文对α-氧化铝陶瓷采用往复式金刚石线锯切割技术,其优势在于:加工范围大、效率高、加工质量好、切缝窄、平面度高、材料损耗低、污染小。并通过往复式金刚石线锯切割α-氧化铝陶瓷实验工作和仿真分析做下述研究:1.简述金刚石线锯切割技术的发展情况以及对于α-氧化铝陶瓷等硬脆性材料的加工现状。基于热力学理论,断裂力学理论,阐述了单颗金刚石磨粒切割α?-氧化铝陶瓷过程中裂纹的产生和材料去除原理,近似于磨削去除材料机理,用物理模型描述单颗粒金刚石磨粒切割α-氧化铝陶瓷机理,利用有限元软件将切割过程的物理模型转换为数学模型进行仿真分析。2.对单颗粒金刚石切割α-氧化铝陶瓷过程中切削热,表面粗糙度,应力应变进行研究,通过利用ANSYS/LS-DYNA对切削过程进行3D模拟,热力耦合,分析在不同走丝速度条件下,工件表面裂纹和形貌情况;将切削温度场拟合进切削过程,研究切割过程中切削热,热应力对刀具应力的影响,切削热分布,磨粒承受应力和工件表面形貌的影响以及切削过程中应变问题。3.自主设计研发多种冷却往复式金刚石线锯切割设备,采用P2级精度双轴承丝杠实现YZ方向自动精密进给,导轮张紧力可调,精确控制工件切片厚度,使切片厚度最小达到0.5mm。能够实现多种冷却,并利用FX2N-16MT三菱PLC实现自动、定时冷却,走丝自动正反转,进给速度、走丝速度数字化控制。4.通过设计控制金刚石线锯切割机冷却装置,实现风冷(20℃)、常温(25℃)水基型KR-C切削液雾化冷却、0℃水基型KR-C切削液冷却等三种冷却。以冷却条件为因素,三种不同冷却方式为水平,并在不同走丝速度和进给速度的条件下,进行正交试验,研究在何种冷却条件下金刚石线锯切割加工工件表面粗糙度Ra最小,并在此冷却条件下,优化线切割工艺参数,减少对于切割工具表面层的损伤、厚度不均、弯曲以及翘曲缺陷等问题。
[Abstract]:Ceramic material is a kind of inorganic nonmetallic traditional material formed by high temperature sintering. It has been applied in mechanical, electronic and biological aspects for a long time. However, in the rapid development of material science, the concept of ceramics has far exceeded the traditional category. Compared with other materials, new ceramics with new chemical elements and precise control of process structure have good electrical resistance, low creep at high temperature, wear resistance, corrosion resistance, high strength and high hardness. A variety of sensitivities beyond the characteristics of traditional ceramics, and widely used in aerospace, energy, biology, metallurgy, electronics, optics and other industries. New ceramic materials can be divided into three categories according to their functional applications: structural ceramics, functional ceramics, bioceramics. Among them, alumina ceramics have been used in structure, function and biology. As a typical representative of new type of ceramics, 伪 -alumina ceramics are not only used to fabricate integrated circuit substrates, human bionic bones, tool knife matrix materials, It is also used for high temperature protection and powder grinding of carrier rocket. However, because of its high hardness and brittleness, 伪-alumina ceramic is a typical hard brittle material, which is limited by traditional machining methods. In order to reduce the roughness of slice surface, reduce the scratch, damage and metamorphism of the surface, this paper adopts the reciprocating diamond wire saw cutting technology for 伪 -alumina ceramics. The advantages of this technology are: wide range, high efficiency, good machining quality, narrow cut seam. High planeness, low material loss and low pollution. And through the reciprocating diamond wire saw cutting 伪-alumina ceramic experimental work and simulation analysis to do the following research: 1. This paper describes the development of diamond wire saw cutting technology and the processing status of 伪-alumina ceramics and other hard brittle materials. Based on the theory of thermodynamics and fracture mechanics, the principle of crack generation and material removal in the process of cutting 伪 -alumina ceramic by single diamond abrasive particle is described, which is similar to the mechanism of material removal by grinding. The physical model is used to describe the mechanism of cutting 伪-alumina ceramics by single grain diamond abrasive particles, and the physical model of cutting process is transformed into mathematical model by finite element software. The cutting heat, surface roughness, stress and strain in the process of cutting 伪 -alumina ceramics with single grain diamond are studied. By using ANSYS/LS-DYNA to simulate the cutting process in 3D, the thermo-mechanical coupling is used to analyze the conditions of different walking speed. The cutting temperature field is fitted into the cutting process to study the influence of cutting heat and thermal stress on the cutting stress, the distribution of cutting heat, The effects of stress on the abrasive particle and the surface morphology of the workpiece and the strain problem during cutting. A variety of cooling reciprocating diamond wire saw cutting equipment was designed and developed independently. The YZ direction automatic precision feed was realized by using P2 grade precision double bearing lead screw. The tension force of the guide wheel was adjustable, and the slice thickness of the workpiece was accurately controlled, which made the slice thickness minimum 0.5 mm. Can realize a variety of cooling, and the use of FX2N-16MT Mitsubishi PLC to achieve automatic, timing cooling, wire automatic forward and reverse rotation, feed speed, wire speed digital control. 4. By designing and controlling the cooling device of diamond wire sawing machine, three kinds of cooling methods are realized, such as air cooling (20 鈩，

本文编号：1884354