Schwartz, Adam J.; Kumar, Mukul; Adams, Brent L.; Field, David P. biên tập (2009). Electron Backscatter Diffraction in Materials Science (ấn bản 2). New York, NY: Springer New York, NY (xuất bản 12 tháng 8 năm 2009). doi:10.1007/978-0-387-88136-2. ISBN978-0-387-88135-5.
↑ Throughout the Wikipedia page, the terms ‘error’, and ‘precision’ were used as defined in the International Bureau of Weights and Measures (BIPM) guide to measurement uncertainty (GUM). In practice, the true value in any measurement is unknowable; therefore, treat ‘error’, ‘accuracy’, and ‘uncertainty’ as synonymous, and ‘true value’ and ‘best guess’ as synonymous. Precision is the variance (or standard deviation) between all estimated quantities. Bias is the difference between the average of measured values and an independently measured ‘best guess’. Accuracy is then the combination of bias and precision.[1]
↑ Strain, distortion, and deformation can refer to several quantities in different fields. Therefore, we define our use of these terms (in italics) as follows. A mechanically loaded object changes shape in response to applied load; when measured in a mechanical test frame, it is called (total) engineering strain. Plastic strain is the shape change that persists after removing the macroscopic load. On the microscale, plastic deformation in most crystalline materials is accommodated by dislocation glide and deformation twinning. However, dislocations are also generated in a material as plastic deformation progresses, and dislocations with similar crystallographic character and sign that end up near each other in a material (e.g., lined up at a slip band) can be characterised as geometrically necessary dislocations (GNDs). Increasing plastic strain in a polycrystal also elastically distorts the crystal lattice to accommodate crystal defects (e.g., dislocation cores), groups of defects (e.g., dislocation cell walls), and maintains compatibility at polycrystal grain boundaries. This lattice distortion can be expressed as a deformation gradient tensor, which can be decomposed into elastic strain (symmetric) and lattice rotation (antisymmetric) components.[86] In this Wikipedia article, we use the term lattice distortion as a general term to refer to elastic distortion components derived from the deformation gradient, elastic strain, and lattice rotation tensors.
