A thermomechanical constitutive model for phase transformations in silicon under pressure and contact loading conditions

作者：Budnitzki M^*; Kuna M

来源：International Journal of Solids and Structures, 2012, 49(11-12): 1316-1324.

DOI：10.1016/j.ijsolstr.2012.02.004

• Silicon
• Constitutive model
• Contact loading
• Stress induced phase transformation
• Reversible phase transition
• Nanoindentation

Most of the technologically relevant abrasive machining techniques for silicon (Si) such as lapping, sawing and grinding are based on the interaction of the silicon surface with a hard particle or asperity. It has been long established that the governing deformation mechanism for Si under such contact loading conditions is stress induced phase transformation. The present work introduces a novel phenomenological constitutive model for phase transformations of silicon set up in a thermomechanical framework of broad applicability. Taking into account experimental observations as well as first principle and molecular dynamics calculations, it captures both the cd-Si -> beta-Si transition upon compression and the beta-Si -> a-Si transition upon rapid decompression, which are most relevant for indenter loading. The model was numerically implemented in analogy to incremental plasticity and successfully applied for finite-element (FE) simulations of nanoindentation.

• 出版日期2012-6-1