Study of Physical and Mechanical Properties and Microstructure of Wood Materials at Different Scale Levels

This article describes the results of a comprehensive study of the physical and mechanical properties of wood (using Scots pine (Pinus sylvestris L.) as an example) at the nano-, micro-, and macroscales and shows their relationship with the anatomical structure at these levels. Size effects in wood hardness, as well as their similarities and differences between earlywood and latewood within annual rings, are identified. Using nanoindentation and scratch testing, the hardness and Young’s modulus distribution profiles are constructed, and their relationship with the structure of wood annual rings is shown. Using SEM image analysis of the cellular structure, density distribution profiles are obtained within wood annual rings, and their correlation with the distribution profiles of physical and mechanical properties is revealed. This makes it possible to use the obtained data both for solving problems in materials science and for other fields of science, such as dendrochronology and dendroclimatology.