2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16
In the construction and manufacturing sectors, traditional consumables are being replaced by high-tech plastics in various designs. They are distinguished by high technical and physical qualities, which allows them to confidently replace both wood and even metal. However, wood raw materials have many advantages due to the low cost of purchase and environmental friendliness. Strength is considered the weak point of this material. To increase this indicator, manufacturers use special processing methods to increase rigidity, density and, in general, resistance to mechanical damage. However, hardwoods naturally have these properties, often eliminating the need for special heat treatments.
Hard wood features
Usually, the quality of such rocks is evaluated by three indicators - density, Brinell hardness and cross-cut stiffness. On average, the density of such wood is about 1200-1400 kg/m3. As for Brinell hardness, this value can reach 3.5 kgf/mm2, and the cross cut hardness is 80 MPa. Again, these figures arefor trees familiar to Russian conditions, and exotic species may have significantly superior characteristics. What types of wood are hardwoods in the temperate zone? Oak, beech, ash and some types of hornbeam are usually distinguished. It is important to consider that along with the positive quality in the form of hardness, such trees also differ in negative properties. It has already been said that in order to improve the performance, lumber can be subjected to additional processing. Sometimes solid wood is also subjected to similar operations to obtain special physical characteristics. And here a serious problem manifests itself, since many rocks, due to their high density, cannot stand the processes of grinding, impregnation, and especially drying. Often cracks, chips and other manifestations of structural deformation are formed.
Hardwood Classifications
Distinguish between species that grow in the temperate zone and exotic trees. There is also a classification into deciduous and coniferous species. Although most hardwoods are still deciduous, among the needles there are also varieties with increased density and stiffness characteristics. As for the rocks of the temperate zone, they include maple, boxwood, briar and the mentioned hornbeam. Coniferous hardwoods are also the most common here. Which of them have the most pronounced indicators of hardness? In this case, larch, yew, juniper and lawson deserve attention. There are hard rocks and among the usualfruit trees - this category includes forest apple, oxalis, pear, mountain ash and some types of walnut. As for exotic rocks, they demonstrate the highest rates of hardness and density. Here, red and lemon trees, rosewood, eucalyptus, etc. are of particular interest. Now it is worth considering in more detail the hardest tree species.
Mahogany
In Russia, this breed is the most popular, as it can be purchased on a free sale. This is a tropical tree, which is characterized by high hardness, as well as the original texture on the cut. Freshly sawn wood has a yellowish-red hue, but over time it is replaced by darker tones, which gives the material nobility. Accordingly, the consumer appreciates not only the technical, but also the decorative properties of this tree. It should be noted that from the point of view of pronounced decorative qualities, backout and boxwood also belong to hardwoods. Moreover, these rocks are used not only as finishing materials, but can also replace individual decorative details in jewelry and technical devices. But mahogany is also distinguished by ease of machining. The density of this rock is not as high compared to many hard materials of tropical origin, so this raw material is in great demand in furniture factories.
Ironwood
If heavy-duty plastics can replace iron due to their strength, then this breedis not only able to take the place of an element resistant to mechanical stress in some areas, but also meets the increased requirements in terms of environmental resistance. The concept of an iron tree includes a whole group of species that mainly grow in the countries of the Asian region and in Australia. The classic representative of the group is the Persian parrotia. This species is common in relic forests, where local residents have been making handles for knives and axes from it since ancient times. Today, the "iron" wood of hardwoods is under the protection of UNESCO. This breed, in particular, has an aesthetic value, which causes great interest in it from the market.
Merbau
This is not the hardest, but in terms of other operational qualities, we can say the most practical breed. Previously, this tree was used in the construction of ships. This is due to the fact that the material is resistant to moisture and also does not dry out. Therefore, merbau can be stored for a long time, after which it can be subjected to heat treatments and used in construction. As already noted, hardwood trees, like hornbeam or beech, practically do not tolerate additional processing. But merbau steadfastly endures traditional methods of influence in order to improve individual performance.
White locust
The hardest rock in Russia, which is valued not only for strength, but also for resistance to biological processes.destruction. In addition, this type of acacia is well polished and does not crack during long-term operation. Subject to preventive treatment measures, wood is also not subjected to minor mechanical damage. By the way, in terms of technical characteristics, this species is superior to such hardwoods as oak and ash.
Backout
The hardness index of this wood is one of the highest in the world. Suffice it to say that the material optimally copes with its tasks when used in the form of bearings, bushings and brackets. In the navy, the wood of this species was often used as deck material. But as lumber, backout is valued for other reasons. It does not lend itself to deforming processes under the influence of third-party negative factors. These can be both chemical and physical influences that do not have a destructive effect on the structure. There are other hardwoods that also show resistance to extreme loads. But the unique quality of the backout is the balanced combination of high mass and density.
Using hardwoods
Most of this material is used in construction. Wood in one form or another can be used as a basis for structures, and as a finish. Separate breeds are also used in the fields of mechanical engineering and instrumentation. Of these, separate functional elements are performed with the expectation of a long-termuse - and it can be both temporary consumables and durable parts of structures. These are the main, but not all, areas in which high-strength wood species are used. Soft, hardwoods, as well as types of wood with average density indicators can also be used for medical purposes. In this case, hardness is not so important. The fact is that many exotic breeds contain resins that are unique in their qualities. Preparation of therapeutic mixtures for internal and external use, in particular, allows you to fight diseases of the joints, respiratory organs, etc.
Conclusion
Building materials manufacturers are well aware of the rule that increasing one technical and operational property almost always entails minimizing other qualities. In part, this law also applies to hardwoods, which, according to some characteristics, lose to softwoods. The processes of biological destruction, physical deformation, as well as texture distortion are the main disadvantages of soft rocks used in the long term. But on the other hand, such wood has the advantage of being susceptible to additional treatments. Of course, there are exceptions in both categories, but the soft structure due to its low density is still more inclined to form new properties artificially.
