基于不同冷卻方式的α-氧化鋁陶瓷線鋸切割機理與工藝研究
發(fā)布時間:2018-05-13 18:42
本文選題:氧化鋁 + 霧化冷卻; 參考:《江蘇科技大學》2015年碩士論文
【摘要】:陶瓷材料是一種經(jīng)過高溫燒結(jié)而形成的無機非金屬傳統(tǒng)材料,在機械、電子、生物方面應用較為久遠,而在材料科學高速發(fā)展的現(xiàn)代,對于陶瓷的概念已遠遠超出傳統(tǒng)范疇。與其他材料相比,通過對工藝結(jié)構(gòu)精密控制、添加新化學元素的新型陶瓷,具有阻電性好、高溫蠕變小、耐磨損、抗腐蝕、高強度、硬度高、多種敏感性等超越傳統(tǒng)陶瓷的特點,并且在航空航天、能源、生物、冶金、電子、光學等行業(yè)廣泛應用。新型陶瓷材料按其功能應用大致可分為三大類:結(jié)構(gòu)陶瓷、功能陶瓷、生物陶瓷。其中氧化鋁陶瓷在結(jié)構(gòu)、功能、生物方面均有應用。α-氧化鋁陶瓷作為新型陶瓷典型代表,不但用于制作集成電路基片,人體仿生骨骼,工具刀基體材料,而且還用于航空運載火箭耐高溫防護,研磨粉體。但由于α-氧化鋁陶瓷硬度高、脆性大,是一種典型的硬脆性材料,受限于傳統(tǒng)的機械加工方法。為降低切片表面粗糙度,減少表面刮痕,損傷,變質(zhì)層,本文對α-氧化鋁陶瓷采用往復式金剛石線鋸切割技術(shù),其優(yōu)勢在于:加工范圍大、效率高、加工質(zhì)量好、切縫窄、平面度高、材料損耗低、污染小。并通過往復式金剛石線鋸切割α-氧化鋁陶瓷實驗工作和仿真分析做下述研究:1.簡述金剛石線鋸切割技術(shù)的發(fā)展情況以及對于α-氧化鋁陶瓷等硬脆性材料的加工現(xiàn)狀;跓崃W理論,斷裂力學理論,闡述了單顆金剛石磨粒切割α?-氧化鋁陶瓷過程中裂紋的產(chǎn)生和材料去除原理,近似于磨削去除材料機理,用物理模型描述單顆粒金剛石磨粒切割α-氧化鋁陶瓷機理,利用有限元軟件將切割過程的物理模型轉(zhuǎn)換為數(shù)學模型進行仿真分析。2.對單顆粒金剛石切割α-氧化鋁陶瓷過程中切削熱,表面粗糙度,應力應變進行研究,通過利用ANSYS/LS-DYNA對切削過程進行3D模擬,熱力耦合,分析在不同走絲速度條件下,工件表面裂紋和形貌情況;將切削溫度場擬合進切削過程,研究切割過程中切削熱,熱應力對刀具應力的影響,切削熱分布,磨粒承受應力和工件表面形貌的影響以及切削過程中應變問題。3.自主設(shè)計研發(fā)多種冷卻往復式金剛石線鋸切割設(shè)備,采用P2級精度雙軸承絲杠實現(xiàn)YZ方向自動精密進給,導輪張緊力可調(diào),精確控制工件切片厚度,使切片厚度最小達到0.5mm。能夠?qū)崿F(xiàn)多種冷卻,并利用FX2N-16MT三菱PLC實現(xiàn)自動、定時冷卻,走絲自動正反轉(zhuǎn),進給速度、走絲速度數(shù)字化控制。4.通過設(shè)計控制金剛石線鋸切割機冷卻裝置,實現(xiàn)風冷(20℃)、常溫(25℃)水基型KR-C切削液霧化冷卻、0℃水基型KR-C切削液冷卻等三種冷卻。以冷卻條件為因素,三種不同冷卻方式為水平,并在不同走絲速度和進給速度的條件下,進行正交試驗,研究在何種冷卻條件下金剛石線鋸切割加工工件表面粗糙度Ra最小,并在此冷卻條件下,優(yōu)化線切割工藝參數(shù),減少對于切割工具表面層的損傷、厚度不均、彎曲以及翹曲缺陷等問題。
[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, 偽 -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, 偽-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 偽 -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 偽-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 偽-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 偽 -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 偽-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 偽 -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,
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