A kind of preparation method of high-compactness pucherite pottery
Technical field
The invention belongs to ceramic material field, be specifically related to a kind of preparation method of high-compactness pucherite pottery.
Background technology
Functional materials is the core of field of new, and the development of new and high technology is played to important promotion and supporting role.In global field of new, functional materials accounts for 85 %.Ceramic material is the important component part of functional materials, has the characteristic of many excellences, is subject to the great attention of scientific and technological circle and business circles.
Pucherite (be called for short 184 Huangs) is a kind of important inorganic yellow pigment, has the characteristics such as nontoxic, color and luster is beautiful, stable chemical nature.Pucherite as the narrower semiconductor material of a kind of band gap (
e g=2.4 eV), having good product oxygen activity under radiation of visible light, is a kind of novel photocatalyst.At present, pucherite is more and more extensive in the application of pigment and photocatalysis field.
According to document, utilize high temperature solid phase synthesis, chemical bath deposition method, sol-gel method, hydrothermal method, the precipitator method etc., can prepare pucherite powder; Utilize crystal pulling method, can prepare pucherite monocrystalline.But, in document, lack up to now the report of relevant pucherite pottery.This is that highly volatile in sintering procedure, makes the product burning till be vesicular structure because of pucherite fusing point lower (~ 940 ℃).Utilize solid reaction process, very difficult sintering goes out fine and close solid pucherite pottery, thereby makes pucherite become blank in function ceramics research field.In view of pucherite is a kind of important semiconductor material, widespread use in photochemical catalysis and pigment field, has the physical propertys such as ionic conductivity, ferroelasticity, photochromic, is necessary to develop a kind of preparation method, prepare the pucherite pottery of excellent property, develop its distinctive functional attributes.
Summary of the invention
Technical problem to be solved by this invention is to overcome the problem that pucherite is difficult to sinter into porcelain, and a kind of method that can prepare high-compactness pucherite pottery is provided.
The present invention solves the problems of the technologies described above adopted technical scheme to be: a kind of preparation method of high-compactness pucherite pottery, and with Bi
2o
3and V
2o
5powder is raw material, through twice, fires and forms, and prepared pucherite ceramic dense degree is more than 97%, and concrete preparation process is:
Step 1, by Bi
2o
3and V
2o
5powder mixes after according to the molar ratio ingredient of 1:1 and packs grinding plant into, adds the dehydrated alcohol of powder total mass 5% as solvent, grinds and volatilizes solvent after 5 hours, and make compressing tablet.
Step 2, compressing tablet is put into the quartz molds of sealing, put into retort furnace pre-burning 12 hours at the temperature of 890 ℃, then annealing cooling naturally.
Step 3, the compressing tablet of pre-burning is ground to form to powder, and under the pressure of 6 Mpa, carry out compressing tablet with oil press, be pressed into diameter 15 mm, the base substrate of thickness 2 mm.
Step 4, the base substrate pressing is placed in the quartz molds of sealing, then put into retort furnace, first the temperature rise rate with 2 ℃/min rises to 500 ℃ by room temperature, keeps after 2 hours, temperature rise rate with 3.25 ℃/min is warming up to 890 ℃, afterwards this temperature lower calcination 12 hours.
After step 5, calcining finish, rate of temperature fall with 1.5 ℃/min is down to 800 ℃ by 890 ℃, then is down to 700 ℃ with the rate of temperature fall of 1.7 ℃/min, is down to 550 ℃ afterwards with the rate of temperature fall of 2.5 ℃/min, with the rate of temperature fall of 3.3 ℃/min, be down to 350 ℃ again, finally naturally cool to room temperature.
Step 6, the sample surfaces after cooling is carried out to polished finish, can obtain orange-yellow pucherite pottery.
The invention has the beneficial effects as follows:
1, when firing, compressing tablet is placed in airtight mould, make compressing tablet form higher vapour pressure around, can effectively suppress the volatilization of composition, thereby avoid forming vesicular structure, make to fire through secondary the pucherite pottery of making and there is higher density.
2, for fear of firing the product causing because cooling rate is too fast after end, shrink too fast and ununiform shrinkage, cooling rate is limited to not higher than 3.3 ℃/min, can prevent that thus product from occurring hole in cooling contraction process, further ensured the high-compactness of product.
3, by the control to the processing condition such as firing temperature, time and parameter, ensured transformation efficiency and the production efficiency of raw material to pucherite pottery, made the pure monoclinic phase pucherite of the final product supporting for existing without other dephasigns.
4, the pucherite ceramic dense degree of preparing by described method can reach more than 97%, and specific inductivity is about 60, and dielectric loss is less than 0.005, is a kind of potential high dielectric function stupalith.
Accompanying drawing explanation
Fig. 1 is preparation technology's schema of pucherite pottery of the present invention;
Fig. 2 is the sample photo of pucherite pottery of the present invention;
Fig. 3 is the XRD figure of pucherite pottery of the present invention.
Embodiment
High-compactness pucherite pottery of the present invention is with Bi
2o
3and V
2o
5powder is raw material, through twice, fires and forms, and specifically can adopt following steps preparation.
Step 1, by Bi
2o
3and V
2o
5powder mixes after according to the molar ratio ingredient of 1:1 and packs grinding plant into, with underhand polish 5 hours, in the time of grinding, take dehydrated alcohol as solvent, can keep uniform particles, also be unlikely to produce powder airborne dust, added dehydrated alcohol amount is 5% left and right of join powder quality.Guarantee can volatilize after grinding complete, can not remain in powder.By compressing tablet after ground powder drying.
Step 2, compressing tablet is put into the quartz molds of sealing, put into retort furnace pre-burning 12 hours at the temperature of 890 ℃, then annealing cooling naturally; In order to avoid the volatilization of composition as far as possible, in quartz molds, pack into after compressing tablet, remaining space is the smaller the better, and the volume size of quartz molds is advisable can just load compressing tablet.
Step 3, the compressing tablet of pre-burning is ground to form to powder, and under the pressure of 6 Mpa, carry out compressing tablet with oil press, be pressed into diameter 15 mm, the base substrate of thickness 2 mm.
Step 4, the base substrate pressing is placed in the quartz molds of sealing, then put into retort furnace, first the temperature rise rate with 2 ℃/min rises to 500 ℃ by room temperature, keeps after 2 hours, temperature rise rate with 3.25 ℃/min is warming up to 890 ℃, afterwards this temperature lower calcination 12 hours.
After step 5, calcining finish, rate of temperature fall with 1.5 ℃/min is down to 800 ℃ by 890 ℃, then is down to 700 ℃ with the rate of temperature fall of 1.7 ℃/min, is down to 550 ℃ afterwards with the rate of temperature fall of 2.5 ℃/min, with the rate of temperature fall of 3.3 ℃/min, be down to 350 ℃ again, finally naturally cool to room temperature.
Step 6, the sample surfaces after cooling is carried out to polished finish, can obtain orange-yellow pucherite pottery, the product of making as shown in Figure 2.
Prepared pucherite ceramic dense degree is more than 97% after testing.Shown in accompanying drawing 3, the pucherite pottery XRD figure of preparing for the present embodiment.With standard P DF card (No. 75-1866) contrast, can determine that the present embodiment gained pottery, for pure monoclinic phase pucherite, exists without other dephasigns.Under room temperature and 1 MHz test condition, the demonstration of impedance analysis result, pucherite ceramic dielectric constant prepared by the present embodiment is about 60, and dielectric loss is less than 0.005, is a kind of potential high dielectric ceramic material.