Studying the Physical and Mechanical Properties of Siberian Larch Wood from the Nanolevel to Macrolevel Using Nanoindentation and Scratch-Test Methods with the Possible Use of Data for Dendrochronology

The study of larch wood is of interest in both engineering and nonengineering fields of science. This is due to the wide area of its growth and dominant position in terms of reserves in the Russian Federation. However, there are technological difficulties associated with its use as a building material due to the peculiarities of its structure and properties. Approaches to studying the physical and mechanical characteristics of wood from the nanolevel to macrolevel are demonstrated. They are focused on identifying the features of the microstructure and their relationship with the physical and mechanical characteristics at various structural levels. Using the dynamic nanoindentation and scratch-test methods, the values of the hardness and Young’s modulus are obtained from the cell wall level to the ring structure of larch wood. At the levels above individual cell wall both characteristics are found to be several times higher in late wood that in early one within annual growth ring. It is shown that the accuracy of determining the width of annual rings from the obtained profile of mechanical properties is no worse than the standard optical method. This makes it possible to use the proposed approach to solve problems of dendrochronology and its related disciplines.