CN103011803A - Leadless ceramic with high thermoelectric effect and preparation method thereof - Google Patents

Abstract

The invention discloses leadless ceramic with a high thermoelectric effect. The component of the leadless ceramic is Ba1-xSrxTi1-yMnyO3, wherein x is more than or equal to 0.2 and is less than or equal to 0.4; and y is more than or equal to 0 and is less than or equal to 0.03. The leadless ceramic is prepared by adopting the following spark plasma sintering method that pure BaCO3, pure SrCO3, pure TiO2 and pure MnO are weighed according to a stoichiometric ratio of the component expression; after the raw materials are ground and mixed by a mortar, the ground raw materials are pre-sintered for 1 to 3 hours in the air atmosphere at a temperature of 1,000 to 1,200 DEG C so as to synthesize powder; then the powder is placed into a graphite die and is sintered by a spark plasma sintering system in vacuum at a temperature of 800 to 1,000 DEG C so as to obtain dense ceramic sintered body; and finally, the ceramic sintered body is subjected to heat treatment for 1 to 3 hours in the air at a temperature of 1,100 to 1,200 DEG C. The ceramic has a high thermoelectric effect of 3 to 6.1K at an approximate room temperature and can be widely applied to an environmental-friendly solid cooling and energy recovering device.

Description

Lead-free ceramics of a kind of high electricity card effect and preparation method thereof

Technical field

The present invention relates to high electric effect stupalith and preparation method thereof that blocks that solid-state refrigeration and energy collecting device are used.

Background technology

In recent years, along with facing mankind day by day serious environmental problem, refrigeration equipment has been proposed without requirements such as freonll-11, quiet and high-energy conversion efficiency, and high electricity card effect material is expected to be applied at solid-state refrigeration plant.Simultaneously, because this effect is reversible, therefore can intend effect with it prepares energy collecting device.At present, high electricity card effect material mainly concentrates in oxide compound and the high polymers film, but because its refrigeration capacity is too low, therefore needs the stupalith of the high electricity card of exploitation effect.It's a pity, high electricity card effect stupalith all contains a large amount of lead ions, has the problem of welding, and therefore the high electricity card of exploitation effect lead-free ceramics becomes urgent problem.

Summary of the invention

The objective of the invention is provides a kind of lead-free ceramics with the high electricity card of room temperature effect and preparation method thereof for the exploitation of solid-state refrigeration and energy collecting device.

High electricity card effect lead-free ceramics of the present invention, its composition is Ba _{1- x} Sr _x Ti _{1- y} Mn _y O ₃, wherein 0.2≤ x≤ 0.4,0≤ y≤ 0.03.

The preparation method of high electricity card effect lead-free ceramics of the present invention is to adopt the discharge plasma sintering method, and step is as follows:

At first, with pure BaCO ₃, pure SrCO ₃, pure TiO ₂With the stoichiometric ratio weighing of pure MnO by the described expression formula of claim 1, after the mortar ground and mixed, 1000 ~ 1200 ^o1 ~ 3 hour synthetic powder of pre-burning in the air atmosphere under the C, the graphite jig of then powder being packed into utilizes the discharge plasma sintering system 800 ~ 1000 ^oUnder the C in the vacuum sintering obtain fine and close ceramic sintered bodies, at last with ceramic sintered bodies in air 1100 ~ 1200 ^oThermal treatment is 1 ~ 3 hour under the C, obtains the lead-free ceramics of high electricity card effect.

Above-mentioned BaCO ₃, SrCO ₃, TiO ₂With the purity of MnO all more than 99%.

The high electricity card effect lead-free ceramics of invention in the electricity card effect of near room temperature more than 3 ~ 6.1K.The preparation of employing discharge plasma sintering method, technique is simple.High electricity card effect lead-free ceramics of the present invention can be widely used in eco-friendly solid-state cooling and energy recycle device.

Embodiment

Further specify the present invention below in conjunction with embodiment.

The expression formula of the high electricity card effect lead-free ceramics of invention is:

Ba _{1- x} Sr _x Ti _{1- y} Mn _y O ₃, wherein 0.2≤ x≤ 0.4,0≤ y≤ 0.03.

Embodiment:

Preparation method: at first, purity is BaCO more than 99% ₃, SrCO ₃, TiO ₂With the stoichiometric ratio weighing of MnO by above-mentioned expression formula, after the mortar ground and mixed, 1100 ^o3 hours synthetic powders of pre-burning in the air atmosphere under the C, the graphite jig of then powder being packed into utilizes the discharge plasma sintering system 900 ^oUnder the C in the vacuum sintering obtain fine and close ceramic sintered bodies, at last with ceramic sintered bodies in air 1200 ^oThermal treatment is 1 hour under the C, obtains high electricity card effect lead-free ceramics.

Test shows, 800 ^oC is following or 1000 ^oCarry out discharge plasma sintering more than the C and all can not obtain fine and close pottery, and 1100 ^oC is following or 1200 ^oHeat-treat more than the C and will cause the decline of material electricity card effect.

It is 0.3mm that the ceramics sample that embodiment is made is ground to thickness, and after silver electrode is coated at the sample two ends ,-40 ~ 70 ^oC tests its electricity card effect with indirect method.

Table 1 has provided and has consisted of each component content of the present invention and their electricity card effect optimum temps and numerical value, and the preparation method is as above-described embodiment.

In all the components of the present embodiment, when x=0.3 reaches yHad optimum performance at=0.01 o'clock: 20 ^oElectricity card effect is 6.1K during C.

Each component content shown in the table l, as adopting conventional sintering method sintering, then the electricity card effect of obtained pottery is all less than 1K.

Claims (2)

1. one kind high electricity blocks the lead-free ceramics of effect, and the composition that it is characterized in that it is Ba _{1- x} Sr _x Ti _{1- y} Mn _y O ₃, wherein 0.2≤ x≤ 0.4,0≤ y≤ 0.03.

2. prepare the method for the lead-free ceramics of high electricity card effect claimed in claim 1, its step is as follows:

At first, with pure BaCO ₃, pure SrCO ₃, pure TiO ₂With the stoichiometric ratio weighing of pure MnO by the described expression formula of claim 1, after the mortar ground and mixed, 1000 ~ 1200 ^o1 ~ 3 hour synthetic powder of pre-burning in the air atmosphere under the C, the graphite jig of then powder being packed into utilizes the discharge plasma sintering system 800 ~ 1000 ^oUnder the C in the vacuum sintering obtain fine and close ceramic sintered bodies, at last with ceramic sintered bodies in air 1100 ~ 1200 ^oThermal treatment is 1 ~ 3 hour under the C, obtains the lead-free ceramics of high electricity card effect.