The mechanical properties of Refractory Materials refers to the strength, elasticity and plastic properties of the material at different temperatures. Usually with the test pressure, bending, wear resistance and high temperature soft creep and other indicators to determine the mechanical properties of Refractory Materials.
1, at room temperature mechanical properties
1.1, room temperature compressive strength It refers to the refractory material at room temperature in the unit area to bear the maximum pressure, such as beyond this value, the material is destroyed. If the total pressure of the specimen is indicated by A, the absolute pressure required for crushing the sample is indicated by P: normal pressure strength = P / A (Pa) In general, the refractory is rarely used during the use Normal temperature of the static load and lead to damage. But the normal temperature compressive strength is mainly that the sintering of products, as well as its organizational structure related to the nature of the method is simple, so it is to determine the quality of the commonly used test items.
1.2, tensile, bending and torsion strength refractory in use, in addition to compression stress, but also by the tensile stress, bending stress and shear stress,Refractory Materials the impact of refractory products, tensile and bending strength of the main factors Its organizational structure, fine particle structure is conducive to the improvement of these indicators.
1.3, wear-resistant refractory wear resistance depends not only on the density of products, strength, but also depends on the mineral composition of the product, the organization and the material particles combined with the firmness. High temperature strength at room temperature, low porosity, dense texture uniform structure, good sintered products always have good wear resistance.
2, high temperature mechanical properties
2.1, high temperature compressive strength
High temperature compressive strength is the material at high temperature unit cross section can withstand the ultimate pressure. As the temperature increases, the strength of most refractory bricks increases, where clay products and high-aluminum products are particularly significant, reaching the maximum at 1000-1200 ° C. This is due to the fact that the viscosity of the melt at high temperatures is higher than that of brittle glass at low temperatures. But the combination between the particles is more solid. When the temperature continues to rise, the strength drops sharply. The refractory strength index of refractory material can reflect the change of the bonding state of the product at high temperature.
2.2, high temperature bending strength High temperature bending strength refers to the material at high temperatures can withstand the unit section of the ultimate bending stress. It characterizes the ability of a material to resist bending at high temperatures. High temperature bending strength, also known as high temperature bending strength or high temperature fracture modulus. The maximum load of a rectangular parallelepiped specimen of a certain size at a high temperature is allowed to be bent on a three point bending device. The high temperature strength of Refractory Materials is closely related to its actual use. Especially for the evaluation of the quality of alkaline direct bonding bricks, high temperature flexural strength is a very important performance. Such as alkaline direct bonding brick high temperature bending strength, the resistance to the temperature gradient due to strong shear stress,Refractory Materials so the product is not easy to use when the phenomenon of peeling. High temperature bending strength of the products will also improve the impact of its material and wear, enhance slag resistance, therefore, high temperature flexural strength as an indicator of product strength indicators. The refractory strength index of refractory material depends mainly on the composition of chemical minerals, the structure and the production process.
2.3, high temperature creep When the material at high temperatures to bear less than its limit of a constant load, resulting in plastic deformation, deformation will increase with time and gradually increase, and even damage the material, this phenomenon is called creep. Therefore, for materials at high temperatures, the strength can not be considered in isolation, but should be temperature and time factors and strength at the same time consider. For example,Refractory Materials the long time in the high temperature work of the hot stove plaid brick damage is due to the gradual softening of the brick body to produce plastic deformation, the strength decreased significantly or even damage, lattice brick creep phenomenon as the main reason for the damage.
It is generally believed that the factors that affect the high temperature creep are:
1) the use of conditions, such as temperature and load, time, the nature of the atmosphere;
2) materials such as chemical composition and minerals;