What is nanometer zirconia composite ceramic powder?

Zirconia is a new structural ceramic material developed in 1970's.  Because of its wear resistance, corrosion resistance, high strength, high melting point characteristics, widely used in metallurgy, electronics, chemical, machinery and other fields.  

As the most important material in advanced ceramics, zirconia ceramic material is an important basic material for the development of modern high-tech industry.  Especially nano oxide ceramics has become the focus of the industry for its special structure and properties.  The following is a brief introduction to the preparation of nano zirconia ceramics powder materials. 

Ni-P coated nanometer zirconia composite powder-nano zirconia powder

The preparation process of Ni-P coated nanometer zirconia (ZrO2) composite powder is firstly to prepare nanometer ZrO2 powder.  Ni-P nano - ZrO2 powder was prepared by chemical precipitation and electroless plating.  Since ZrO2 has no autocatalytic activity in electroless nickel plating solution, it is necessary to pretreat ZrO2 nanoparticles.  In general, Pd2+ is adsorbed on the surface of ZrO2 powder by one-step palladium catalytic method, and then Pd2+ is reduced to Palladium in the reduction solution, so that the surface of nano-powder has catalytic activity of electroless nickel plating.  The two-step sensitization - activation method is usually used for the pretreatment of non-conductive powders.  However, residual nickel ions in powder are difficult to remove after two-step treatment, which often adversely affects the activity of powder.  

At present, Ni-P coated nano-zirconia composite powder has been widely used and studied in semiconductor nanomaterials.  

Nano zirconia powder - toughened alumina ceramic composite powder  

Zirconia toughened alumina ceramics are one of the most widely studied structural ceramics.  The toughening mechanism of zirconia toughened alumina ceramics is matrix grain refinement, phase transformation toughening, microcrack toughening and crack turning and bifurcation.  The properties of zirconia toughened alumina ceramics are mainly determined by the microstructure formed during sintering, and the microstructure is mainly determined by the powder state of raw materials.  Therefore, the preparation of high quality Al2O3/ZrO2 nano-composite ceramic powder is the premise of preparing zirconia toughened alumina ceramics with excellent performance.  The preparation methods of Al2O3/ZrO2 nano-composite ceramic powder mainly include mechanical mixing method, multiphase suspension mixing method, sol-gel method. Alumina is a kind of high strength matrix in zirconia toughened alumina composite ceramic system, and zirconia in intercalation provides phase transformation toughening mechanism.  The toughening of ceramic materials by ZrO2 phase transformation is still one of the main research topics in the future.  

Zirconia toughened alumina composite ceramics have excellent corrosion resistance, thermal shock resistance, high strength, high toughness, and broad application prospects.  Zirconia toughened alumina composite ceramics can be used to make ceramic cutting tools for cast iron and alloy processing. It can make interface structure of engineering ceramics and prolong the service life of engineering materials.  Alumina toughened with zirconia can be used to make wear-resistant ceramic balls.  Due to its good biocompatibility, alumina can also be used as a biomedical material for the reconstruction and repair of hard tissues (teeth).  

Boron nitride - nano zirconia powder 

Boron nitride - zirconia composite powder was prepared by mechanical mixing method.  Boron nitride, zirconia and additives as the main raw materials.  After mixing, the powder is ball milled and mixed in an alcohol medium, and then sintered in a hot pressing sintering furnace.  Due to the poor sintering ability of pure boron nitride, sintering densification is difficult, generally adding CaO, B2O3, Al2O3, ZnO as sintering additives.  

Boron nitride - zirconia composite ceramics have high strength, high toughness, high thermal conductivity, low expansion, as well as chemical inertia, chemical corrosion in molten metal and other excellent physical and chemical properties.  In addition, it also has excellent thermal shock resistance, erosion resistance, wear resistance and easy processing properties, so that the material is suitable for thin strip continuous casting side sealing plate, jet forming liquid pipe, metal spinneret nozzle, continuous casting functional refractory materials and other fields.  

Nano cerium zirconium composite oxide powder-nano zirconia powder 

The preparation methods of nano-cerium zirconium composite oxide powder include high-temperature roasting method, sol-gel method, coprecipitation method, hydrothermal method and solid reaction method.  Al2O3 doped CeO2 coated monoclinic zirconia powders with particle size less than 100 m were prepared by high temperature pyrolysis of suspension consisting of Al(NO3)3•9H2O•Ce(NO3)3•6H2O and monoclinic zirconia nano-powders by roasting in water-ethanol solvent.  Nano-cerium zirconium composite oxide material is mainly used as auxiliary catalyst for automobile tail gas treatment. It has good high temperature stability, high REDOX capacity, high oxygen storage and release capacity.