【摘要】：運(yùn)用分子動力學(xué)仿真模擬高速磨削下單顆金剛石磨粒切削單晶硅的過程,通過分析切屑、相變、位錯(cuò)運(yùn)動并結(jié)合工件表面積的演變規(guī)律研究磨削速度對亞表層損傷和磨削表面完整性的影響.仿真結(jié)果顯示:磨削速度的增大會加劇磨粒前端材料的堆積,超過200 m/s后增加不再明顯.而加工區(qū)域的平均溫度通過原子之間的擠壓和摩擦?xí)粩嘣龃?在磨削溫度、磨削力以及粘附效應(yīng)的相互作用下,摩擦系數(shù)先增大后減小.晶格的變形、晶格重構(gòu)和非晶相變導(dǎo)致切屑形成過程中的磨削力劇烈波動.研究結(jié)果表明:在加工脆性材料單晶硅過程中,隨著磨削速度的升高亞表層損傷厚度先減小后增大.當(dāng)磨削速度低于150 m/s時(shí),隨著磨削速度的升高,磨粒下方的原子晶格重新排列的時(shí)間縮短,非晶結(jié)構(gòu)的產(chǎn)生減少,亞表層損傷厚度減小.當(dāng)磨削速度超過150 m/s時(shí),加工區(qū)域中的高溫成為主導(dǎo)因素促進(jìn)位錯(cuò)的成核、運(yùn)動致使亞表層損傷厚度增大.
[Abstract]:The molecular dynamics simulation is used to simulate the cutting process of monocrystalline silicon by high speed grinding order diamond abrasive. The effects of grinding speed on subsurface damage and surface integrity of workpiece are studied in combination with dislocation movement and the evolution of workpiece surface area. The simulation results show that the increase of grinding speed will aggravate the accumulation of abrasive front end materials, but the increase will not be obvious when the grinding speed exceeds 200 m / s. The average temperature of the processing area increases through the squeezing and friction between atoms. The friction coefficient increases first and then decreases under the interaction of grinding temperature, grinding force and adhesion effect. Lattice deformation, lattice reconstruction and amorphous phase transition lead to severe fluctuation of grinding force during chip formation. The results show that the damage thickness of subsurface layer decreases firstly and then increases with the increase of grinding speed in the process of machining brittle material monocrystalline silicon. When the grinding speed is less than 150 m / s, with the increase of grinding speed, the rearrangement time of atomic lattice under the abrasive particle is shortened, the formation of amorphous structure is reduced, and the damage thickness of subsurface layer is reduced. When the grinding speed is more than 150 m / s, the high temperature in the processing area becomes the dominant factor to promote the nucleation of dislocation, and the motion results in the increase of the damage thickness of the subsurface layer.
【作者單位】： 太原理工大學(xué)機(jī)械工程學(xué)院精密加工山西省重點(diǎn)實(shí)驗(yàn)室;
【基金】：國家自然科學(xué)基金項(xiàng)目(51575375) 山西省研究生教育創(chuàng)新項(xiàng)目(2017BY044)資助~~
【分類號】：TQ127.2
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本文編號：2211545