Fiber reinforced aluminum titanate composite material and preparation method of products thereof

Abstract

The invention discloses fiber reinforced aluminum titanate composite material and a preparation method of products thereof. Alpha-Al2O3 and titanium yellow powder taken as raw material are in-situ synthesized into aluminum titanate by adopting one-step method, stabilizing agent for preventing the aluminum titanate from being decomposed and mullite fiber with reinforcement effect are added in the batch mixture, vacuum slip casting is performed after wet ball milling in a ball mill, and the products are obtained by sintering after being dried. The material comprises the following components of raw materials: 49 to 55 percent of Alpha-Al2O3, 35 to 42 percent of titanium yellow powder, 3 to 6 percent of stabilizing agent, and 3 to 6 percent of mullite fiber, wherein, the stabilizing agent is compounded by magnesium oxide and cerium oxide. The prepared fiber reinforced aluminum titanate composite material has the advantages of small thermal expansion coefficient, high thermal stability and chemical stability, and can greatly improve the service life of composite material. Vacuum slip casting is adopted, the technology is simple, the microstructure texture of the product is uniform, and the products can be used for preparing cast aluminum riser tubes, thermoelectric couple protecting sleeves and crucibles, and other products.

Description

technical field [0001] The invention belongs to the technical field of refractory materials, and in particular relates to a fiber-reinforced aluminum titanate composite material and a preparation method of the composite material product. Background technique [0002] Due to its high melting point, low expansion and excellent thermal shock resistance, aluminum titanate ceramics have broad application prospects in metallurgy, automobiles, and military industries. However, the crystal structure of aluminum titanate sintered body is pseudobrookite type, belonging to orthorhombic system, with anisotropy of thermal expansion coefficient, and there is a tendency of local internal stress concentration at the grain interface along with heating and cooling. The resulting offset causes tiny cracks or voids, resulting in a decrease in mechanical strength, especially when the load is applied at high temperatures, it cannot exert sufficient durability, which limits the practical applicati...

AI Technical Summary

Problems solved by technology

The strength of the composite material with a silicon carbide content of 7% (mass fraction) can be increased to 170%, while the thermal expansion coefficient does not change significantly, but the price of whiskers is expensive, and silicon carbide is easily oxidized in an oxidizing atmosphere at high temperature, which makes Composite performance degradation

Al 2 o 3 Although the fiber has the characteristics of high elastic modulus and good impregnation, but the Al 2 o 3 Fiber-reinforced aluminum titanate materials must be pre-synthesized to stabilize aluminum titanate in order to avoid titanium oxide and Al 2 o 3 Fiber pulverization caused by fiber reaction, which causes the fiber to lose its reinforcing effect

Some people have also studied the influence of mullite fiber on the mechanical properties of aluminum titanate ceramics, but the raw material is pre-synthesized aluminum titanate, and the molding process is dry pressing after adding a binder, which will inevitably cause mullite The reduction of the aspect ratio of stone fibers and the bending and agglomeration of fibers cannot make the fibers well and evenly dispersed into the matrix to play a reinforcing effect