本文關(guān)鍵詞：激光熔蝕內(nèi)部孔穴形態(tài)及相態(tài)變化　出處：《化工學(xué)報(bào)》2017年S1期 　論文類型：期刊論文

  更多相關(guān)文章： 脈沖激光 內(nèi)部空穴 相變 分子模擬 微尺度

【摘要】：采用分子動(dòng)力學(xué)方法對(duì)皮秒脈沖激光在晶體材料內(nèi)部熔蝕出空穴的過程進(jìn)行了模擬研究。通過記錄整個(gè)燒蝕過程中粒子速度和位置的變化得到了材料形態(tài)變化的原子圖像;同時(shí),對(duì)粒子動(dòng)能和受力進(jìn)行統(tǒng)計(jì)分析得到了整個(gè)材料內(nèi)部的應(yīng)力傳導(dǎo)和溫度變化分布,并利用P-T相圖對(duì)特定位置處的材料相態(tài)變化進(jìn)行了分析。結(jié)果表明:僅處于特定能量密度范圍內(nèi)的皮秒脈沖激光可在晶體材料內(nèi)部加工出孔穴;激光能量在燒蝕點(diǎn)處的累積以及轉(zhuǎn)化會(huì)導(dǎo)致材料內(nèi)部出現(xiàn)極強(qiáng)的應(yīng)力波,并且應(yīng)力的傳遞將導(dǎo)致燒蝕點(diǎn)處熔池中材料的噴濺與分離,并使材料內(nèi)部產(chǎn)生結(jié)構(gòu)缺陷;此外,在分析材料內(nèi)部的溫度分布時(shí)可以發(fā)現(xiàn)激光燒蝕過程中的熱影響區(qū)極小,并且大部分在加熱過程中被破壞的晶格結(jié)構(gòu)在材料冷卻后能得到恢復(fù),但晶體材料中仍會(huì)存在分散的片狀晶格缺陷。
[Abstract]:A molecular dynamics method is used to simulate the cavitation process of a picosecond pulse laser in the crystal material. Recorded by changes in particle position and speed of the ablation process obtained atomic images of morphological changes of the material; at the same time, the particle kinetic energy and stress were analyzed by the entire material internal stress conduction and temperature distribution, and the use of P-T to the specific location of the phase diagram of phase change materials is analyzed. The results showed that: only in the picosecond pulse laser specific energy density range in crystal materials processed inside cavity; laser energy accumulated in the ablation point and the transformation will lead to internal stress of strong wave, transfer and stress will lead to expulsion and separation of the ablation point in the weld pool. And the material internal structure defects; in addition, in the analysis of the temperature distribution inside the material can be found in the heat affected zone of the laser ablation process is extremely small, and most of the lattice structure in the heating process can be recovered in the destruction of the material after cooling, but the crystal materials remain scattered lamellar lattice defects.
【作者單位】： 中國海洋大學(xué)工程學(xué)院;
【基金】：國家自然科學(xué)基金項(xiàng)目(51376164)~~
【分類號(hào)】：TN249
【正文快照】： 引言自1960年激光器問世以來,領(lǐng)域內(nèi)眾多學(xué)者就對(duì)材料受激光點(diǎn)源輻照后產(chǎn)生的變化展開了大量的理論以及實(shí)驗(yàn)研究[1-2]。激光加工因其非接觸性以及超精細(xì)加工能力被廣泛地應(yīng)用于理論研究和工程實(shí)踐中,部分學(xué)者嘗試將激光應(yīng)用于加工微槽道[3-5],這部分研究著重關(guān)注了材料被高能，

本文編號(hào)：1340574