High toughness characteristics of zirconia ceramics
Ceramics are the earliest man-made materials produced by physicochemical methods. However, the brittleness of ceramics has always been its Achilles heel. If you can overcome this weakness, coupled with its original wear-resistant, high temperature, corrosion resistance and other very valuable performance, then the future of ceramic materials will be far more than the modern high-quality alloy.
Fortunately, after the tireless efforts of scientists, finally developed a high toughness zirconia ceramics.
First, start by improving the internal structure. The results show that in the ceramic raw materials add a small amount of yttrium oxide, magnesium oxide, calcium oxide and other powders, after the high-temperature refining of zirconia ceramics, wherein the zirconia produces two kinds of crystals: cubic crystals and square crystals. When ceramics are subjected to external forces, the square crystals become a single oblique crystal, and the volume expands rapidly. Because of the rapid increase in the volume of crystals, which can prevent the original micro-cracks in the ceramic expansion, ceramics will not rupture. Some people have added zirconium dioxide to alumina billet, when the amount of the substrate volume is 15%, the hardness of ceramics can be increased by 3 times times, some people call it "ceramic steel".
Secondly, the fiber is distributed evenly in the ceramic material to improve the strength and toughness of the ceramic, which is similar to the addition of the paper tendons in lime. This is because the fiber is added to the ceramic material, has the following three major roles: fiber is not easy to pull off, at work can bear most of the external load, reduce the burden of ceramics, so that cracks are not easy to produce; fiber and ceramic body together, with a lot of friction, so, the toughness of ceramics can be greatly increased Even if there is a slight crack in the ceramics, the fibres can hold them tightly so that the cracks do not expand further.