CAJ | 학술논문

通过在关键区域采用分子动力学（原子）描述、在远场弹性变形区域采用有限元（连续介质力学）描述建立了单晶硅纳米切削的多尺度模型。在边界区域,分子动力学和有限元互为彼此提供边界条件从而实现分子动力学区域和有限元区域的耦合。利用多尺度模型研究了单晶硅的纳米切削过程,结果表明纳米切削中工件以推挤的方式在刀具前方形成切屑。纳米切削中工件的原子键长分布、不同配位数的原子数变化和工件MD区域的原子构型的研究表明,纳米切削中发生了4配位的金刚石立方α-Si向6配位的β-Si结构的转变,即相变是纳米切削中硅的主要变形机制。该研究实现了单晶硅纳米切削的多尺度建模,为进一步探索纳米切削的微观机理提供了一种有效手段。
통과재관건구역채용분자동역학（원자）묘술、재원장탄성변형구역채용유한원（련속개질역학）묘술건립료단정규납미절삭적다척도모형。재변계구역,분자동역학화유한원호위피차제공변계조건종이실현분자동역학구역화유한원구역적우합。이용다척도모형연구료단정규적납미절삭과정,결과표명납미절삭중공건이추제적방식재도구전방형성절설。납미절삭중공건적원자건장분포、불동배위수적원자수변화화공건MD구역적원자구형적연구표명,납미절삭중발생료4배위적금강석립방α-Si향6배위적β-Si결구적전변,즉상변시납미절삭중규적주요변형궤제。해연구실현료단정규납미절삭적다척도건모,위진일보탐색납미절삭적미관궤리제공료일충유효수단。
This paper features the development of Multiscale model of nanometric cutting of single crystal silicon by treating the critical region with MD（atomistic description） and capturing ＂far-field＂ elastic deformations using FE（continuum description）.A HS region is used to couple the MD and FE regions.At the edge of HS region each description provides displacement boundary conditions for the other to realize the concurrent multiscale simulation.The investigation into Nanometric cutting process of single crystal silicon using the multiscale model shows that during nanometric cutting of single crystal silicon,the chip in front of the tool is formed by extrusion.Investigations of the distributions of atomic bond length,the variations of number of atoms with specified nearest number of neighbors,and the atomic configurations of MD region of the workpiece reveal that there occurs a phase transformation from four fold coordinated diamond cubic phase（α-Si） to the six fold coordinated β-Si during the nanometric cutting process,namely the conclusion that phase transformation is the dominant deformation mechanism of single crystal silicon during the nanometric cutting process.The study marked by the development of the multiscale model of nanometric cutting of single crystal silicon provides an effective tool for further exploring the microscale mechanisms of nanometic cutting.