發(fā)布時間：2018-03-31 21:10

  本文選題：超聲珩磨　切入點：空化泡潰滅　出處：《中北大學(xué)》2017年碩士論文

【摘要】：超聲珩磨時近壁面附近的空化泡在經(jīng)過一系列膨脹-收縮-潰滅的泡壁運動后,會對壁面產(chǎn)生高溫高壓的空蝕作用。壁面的空蝕效果主要是受到由空化泡潰滅而產(chǎn)生沖擊波和微射流的沖擊影響。而壁面材料的形變也可能是受到空化泡潰滅壓力場的作用。本論文以超聲珩磨時磨削液中產(chǎn)生的空化泡作為研究對象,應(yīng)用空化泡動力學(xué)、沖擊波的界面?zhèn)鞑ズ筒牧鲜�效準則等理論,分析超聲珩磨參數(shù)以及空化泡初始半徑對空化泡潰滅壓力場和沖擊波的影響,并對材料失效所需沖擊波和微射流的閾值進行計算。最后通過超聲振動試驗研究不同條件下工件材料表面受到空化泡潰滅沖擊作用的表面質(zhì)量變化情況。這為進一步研究超聲珩磨時空化泡潰滅對固壁面的沖擊作用提供了理論和試驗基礎(chǔ)。本論文的主要工作和結(jié)論如下:(1)建立了熱-力耦合超聲珩磨單磨粒磨削有限元模型,仿真結(jié)果表明:磨粒刃圓半徑處于0.1μm和10μm左右,一定磨削深度下的磨粒刃口處切屑發(fā)生塑性去除,且磨削熱效應(yīng)對其具有促進作用;而磨粒刃圓半徑處于1μm左右,磨粒刃口處切屑幾乎沒有塑性流動的現(xiàn)象,磨削熱效應(yīng)亦不明顯。(2)在超聲珩磨磨削區(qū)環(huán)境壓力下,推導(dǎo)出空化泡潰滅時泡外壓力場分布的數(shù)學(xué)模型,并分析空化泡體積比對最大壓強的數(shù)值和位置的影響。分析得到:超聲珩磨磨削區(qū)空化泡潰滅壓力場對大多數(shù)壁面金屬材料的影響屬于彈性變形,其對壁面的空蝕作用沒有直接的影響。(3)以超聲珩磨時磨削液中產(chǎn)生的空化泡為研究對象,考慮液體表面張力,推導(dǎo)出空化泡最大半徑的理論模型,計算得到空化泡最大半徑在歸一化時間為0.751時取得最大值。該數(shù)值隨著聲壓振幅和空化泡初始半徑的增加而增大,而隨著珩磨壓力的增大而減小�？栈�泡初始半徑越小,其最大半徑相對于其初始半徑的放大倍數(shù)越大。(4)理論推導(dǎo)得到超聲珩磨磨削區(qū)單空化泡泡能模型,并分析在一個超聲周期內(nèi)三個特征時刻點處,泡能受到聲壓振幅、珩磨壓力和空化泡初始半徑的影響。結(jié)果發(fā)現(xiàn):對于以上三種參數(shù)均在歸一化時間為0.249周圍,空化泡泡能達到最大;相對于聲壓振幅和珩磨壓力,空化泡初始半徑對泡能的變化起主要的影響。結(jié)合強爆炸理論給出的爆炸能與引起的沖擊波傳播速度和壓強的關(guān)系,在其它條件恒定不變的情況下,得到空化泡潰滅沖擊波和泡能受到以上三種參數(shù)的作用趨勢相同,且相應(yīng)的也是空化泡初始半徑對其潰滅沖擊波的影響最大。(5)理論計算得到,當(dāng)?shù)竭_壁面時的空化泡潰滅沖擊波強度大于203.77MPa時,就能使固壁面材料2024Al發(fā)生塑性變形;對應(yīng)的壁面材料發(fā)生塑性變形下,需要到達固壁面的微射流速度大于262.59m/s。(6)搭建超聲振動的沖擊試驗平臺,試驗發(fā)現(xiàn):隨著試驗時間的增加,工件表面的粗糙度和維氏硬度都增加,并經(jīng)過一定的快速增長后分別在不同的時間點進入緩慢遞增階段;隨著超聲振幅的增加,工件表面的粗糙度和維氏硬度先快速增長,在10.8μm左右達到最大值;工件表面的粗糙度與試驗溶液粘滯系數(shù)的變化趨勢相反,并且實驗前后的工件表面的粗糙度和維氏硬度有一定的正相關(guān)性。超聲振動空化泡潰滅對固壁面的沖擊試驗對研究超聲珩磨磨削區(qū)空化泡潰滅對固壁面的沖擊效果具有一定的指導(dǎo)意義。
[Abstract]:Ultrasonic honing of the cavitation bubble near the wall after a series of expansion and contraction - collapse of bubble wall motion, cavitation will produce high temperature and high pressure on the wall. The wall of the cavitation effect is mainly affected by the shock wave and cavitation bubble collapses by micro jet impact and wall deformation. The material may also be affected by cavitation bubble collapses. The pressure field generated in the ultrasonic grinding liquid honing of cavitation bubble as the research object, the application of cavitation bubble dynamics, the theory of wave propagation and the impact of the interface material failure criteria, analysis of Ultrasonic Honing Parameters and the initial radius of cavitation bubbles on the influence of cavitation bubble collapse pressure field and shock wave, and the failure of materials required for shock wave and micro jet threshold were calculated. Finally through the experimental study on ultrasonic vibration under different conditions of the workpiece surface by the impact of the cavitation bubble collapse The change of surface quality. It is of bubble collapse provides a theoretical and experimental basis for further research on the impact of solid wall ultrasonic honing space. The main work and conclusions are as follows: (1) the establishment of the thermo mechanical coupling of ultrasonic honing single grinding finite element model, the simulation results show that: the grain edge the radius of the circle is 0.1 M and 10 m, the abrasive grinding depth under certain edge at the mouth of the chip plastic removal and grinding, thermal effect has a promoting effect on it; and the abrasive edge radius is about 1 m, abrasive cutting edge cutting almost no plastic flow the phenomenon of grinding heat effect is not obvious. (2) in the environmental pressure grinding zone of ultrasonic honing, deduces the cavitation bubble broken mathematical model of pressure field distribution, and analyzes the influence value and position of cavitation bubble volume ratio on the maximum pressure. Results: the ultrasonic honing grinding area Of bubble collapse pressure field effect on most wall metal material is elastic deformation, which has no direct effect on the wall surface of the cavitation effect. (3) in ultrasonic honing when grinding fluid cavitation bubble as the research object, considering the surface tension of the liquid, a theoretical model derived from the maximum radius of the cavitation bubble, calculated the maximum radius of cavitation bubble in the normalized time 0.751 gets the maximum value. The value increases with the increase of initial radius of cavitation bubble and the sound pressure amplitude, and decreases with increasing pressure. Honing the initial radius of cavitation bubbles is smaller, the maximum radius relative to the initial radius of the greater the magnification (4) deduced from the theory. The ultrasonic honing grinding zone single bubbles model, and analyze the three characteristics of time points in a cycle of bubble by ultrasonic, sound pressure amplitude, initial radius of cavitation bubble and honing pressure. The influence of the Now, for the above three parameters were normalized in time for 0.249 around, bubbles can reach the maximum; relative to the pressure amplitude and honing pressure. The influence of the initial radius of cavitation bubble mainly on global energy changes. With the strong explosion theory gives explosion caused by the shock and the relationship between wave velocity and pressure, constant at other conditions are constant, by shock wave and cavitation bubble collapses bubble can be above three parameters of the same trend, and is also the largest initial radius of cavitation bubble collapse shock wave effect. (5) the theoretical calculation, when reaching the wall when the shock wave intensity is greater than the cavitation bubble collapses 203.77MPa, can make the solid wall material of 2024Al plastic deformation occurred; corresponding wall materials under plastic deformation, need to reach solid wall surface of the micro jet velocity is greater than 262.59m/s. (6) to build the impact of ultrasonic vibration The test platform, the test showed that: with the increase of test time, workpiece surface roughness and hardness are increased after Vivtorinox, and the rapid growth of certain respectively at different time points into the slowly increasing stage; with the increase of ultrasonic amplitude, surface roughness and hardness of the first Vivtorinox rapid growth, reaching a maximum at 10.8 m; the change trend of workpiece surface roughness and test solution viscosity contrast, and surface roughness of the workpiece before and after the experiment and Vivtorinox hardness had a positive correlation. The ultrasonic vibration cavitation bubble collapse on the solid wall surface of the impact test for the study of ultrasonic cavitation bubble collapse honing grinding zone has certain guiding significance to the solid the wall of the impact.

【學(xué)位授予單位】：中北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TG663;TG580.67

【參考文獻】

相關(guān)期刊論文 前10條

1 吳強;姚澄;朱昌平;韓慶邦;;超聲清洗過程環(huán)境壓力對聲空化效應(yīng)的影響[J];應(yīng)用聲學(xué);2015年05期

2 劉國東;祝錫晶;郭策;;功率超聲珩磨磨削區(qū)單空化泡動力學(xué)及其輻射聲場[J];中北大學(xué)學(xué)報(自然科學(xué)版);2013年04期

3 王勇;林書玉;莫潤陽;張小麗;;含氣泡液體中氣泡振動的研究[J];物理學(xué)報;2013年13期

4 劉麗娟;呂明;武文革;;Ti-6Al-4V合金的修正本構(gòu)模型及其有限元仿真[J];西安交通大學(xué)學(xué)報;2013年07期

5 孟慶當(dāng);李河宗;董湘懷;彭芳;王倩;;304不銹鋼薄板微塑性成形尺寸效應(yīng)的研究[J];中國機械工程;2013年02期

6 張振福;曾新吾;陳聃;王一博;;水下沖擊波聚焦作用下空化效應(yīng)的實驗研究[J];實驗流體力學(xué);2012年05期

7 言蘭;姜峰;融亦鳴;;基于數(shù)值仿真技術(shù)的單顆磨粒切削機理[J];機械工程學(xué)報;2012年11期

8 沈壯志;柳楠;;文丘里管反應(yīng)器空化泡的動力學(xué)特性[J];陜西師范大學(xué)學(xué)報(自然科學(xué)版);2012年01期

9 盧義剛;吳雄慧;;雙泡超聲空化計算分析[J];物理學(xué)報;2011年04期

10 劉濤;王江安;宗思光;王雨虹;;激光空泡在剛性壁面附近空蝕特性[J];強激光與粒子束;2011年02期

，

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