Evaluations on Microscopic Images of Heat Treated Spruce and Ash Wood

Heat treatment (thermal treatment) is, a wood modification method and as an alternative to chemical treatment in wood preservation, applied to some extent in improving wood quality. two different species, picea abies and fraxinus excelsior, lumbers were subjected to industrial heat treatment process called as thermowood with actual temperature of 212 0c and duration of 120 minutes. wood sections (cross-section, radial and tangential sections) investigated via light microscope and sem (scanning electron microscope). during laboratory works, we faced to face much more technical difficulties on sectioning heat treated woods in comparison with control samples. to have successful sectioning and better visual materials for image analysis, paraffin embedding applied. it is also recommended some modifications for the procedure of micro sections. in this study, we have some observations such as more cracks, fragmentations in rays and early - latewood parts on heat treated micrographs which are not observed similarly on control samples indicating that heat treated wood become more brittle after treatment. therefore, heat treatment effects on microstructure should be taken into account while interpreting the causes of mechanical decreases of heat-treated wood.