CN100459201C - Thermoelectric material and method for producing same - Google Patents
Thermoelectric material and method for producing same Download PDFInfo
- Publication number
- CN100459201C CN100459201C CNB2003801043786A CN200380104378A CN100459201C CN 100459201 C CN100459201 C CN 100459201C CN B2003801043786 A CNB2003801043786 A CN B2003801043786A CN 200380104378 A CN200380104378 A CN 200380104378A CN 100459201 C CN100459201 C CN 100459201C
- Authority
- CN
- China
- Prior art keywords
- thermoelectric material
- sintering
- under
- conductive coefficient
- particle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/80—Constructional details
- H10N10/85—Thermoelectric active materials
- H10N10/851—Thermoelectric active materials comprising inorganic compositions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02N—ELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
- H02N11/00—Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10N10/00—Thermoelectric devices comprising a junction of dissimilar materials, i.e. devices exhibiting Seebeck or Peltier effects
- H10N10/01—Manufacture or treatment
Abstract
A thermoelectric material having an average particle diameter of crystal of 50 nm or less and a relative density of 85 % or higher is disclosed. A method for producing the thermoelectric material comprises a step of preparing a micro powder and a step of sintering or solidifying the micro powder under a pressure of 1.0-10 GPa.
Description
Technical field
The present invention relates to constitute the thermoelectric power generation that utilizes Seebeck effect and utilize Peltier effect directly to cool off the thermoelectric material of the thermoelectric element of heating usefulness.As the thermoelectric material that this thermoelectric element is used, known have a Bi
2Te
3The CoSb of system, skutterudite type structure
3The ZrNiSn of series intermetallic compound, half whistler (MgAgAs) type structure etc., Fe Si
2, Fe Si
1.73Deng.
Background technology
Utilize the thermoelectric power generation of Seebeck effect and utilize Peltier effect directly to cool off the pyroelectric technology of heating, compare, have following feature with adopting existing technology of compressors:
The formation of system simple, can miniaturization
2. do not use coolants such as fluorine Lyons
3. do not have movable part, durability, reliability and quietness are good
It is a kind of potential very good technology.But, present present situation is, because the effciency of energy transfer that thermoelectric element produces is lower than the system that adopts existing compressor, so only in the cooling of high performance CPU and the long LD that uses apart from optical communication, and portable refrigerator etc. is gone up and is used as Peltier element.For the application that enlarges this pyroelectric technology must improve conversion efficiency, the pyroelecthc properties of thermoelectric material is improved.
The performance of thermoelectric material can be represented with the performance index that following formula is represented.
Z＝S
2/(ρ·κ)
In the formula,
S: Seebeck coefficient (V/K)
ρ: than resistance (Ω m)
κ: conductive coefficient (W/mK)
Hence one can see that, and in order to improve the performance of thermoelectric material, effective method is to increase Seebeck coefficient, reduces than resistance and conductive coefficient.
Seebeck coefficient is owing to result from the electronic structure of material, so substantially by material with form decision.Therefore, if will increase Seebeck coefficient, importantly explore material system and make dopant species and the quantity optimization.In contrast to this, not only be subjected to the influence of electronic structure, but also be subjected to the influence of lattice vibration and impurity etc. than resistance.And conductive coefficient, in its big or small main cause of decision, the contribution of lattice vibration occupies over half usually in the high performance thermoelectric material.Therefore we can say that if will reduce than resistance and conductive coefficient, the organizational controls on the material engineering etc. is considerable.
The research of the pyroelectric material performance raising aspect of carrying out in the past, purpose is to reduce conductive coefficient, and the granular by tissue and import impurity etc. and increase phon scattering.For example, open in the clear 56-136635 communique, disclose a kind of passing through ultra-micro powder and big two kinds of powder, the sintering of Bi Qi particle diameter are obtained the method for sintered body very close to each other between particle, that density is high the spy.And the manufacture method of the ultra-micro powder of using as raw material, can see the technology of opening disclosed employing arc plasma sputtering method on flat 2-27779 communique etc. the spy.After the spy opens synthesis material fine-particle powders such as disclosing a kind of employing solwution method in the 2000-252526 communique, its sintering is made the method for thermoelectric material.Open in the 2000-349354 communique the spy, utilize mechanical alloying method to make fine-particle powder, by its plasma agglomeration being made the method for thermoelectric material.
And open in the flat 10-209508 communique the spy, a kind of method that particle diameter is in more than 50 nanometers by making, the charge carrier diffusion length improves performance to get off is disclosed, in a single day particle diameter is reduced to performance is reduced on experience.Though do not mention the reason that this performance reduces, it is believed that to make crystal grain reduce to make impurity to increase and the relative density reduction.And, open in the 2002-76452 communique the spy, the thermoelectric (al) inversion material that a kind of particle size distribution is piled up or disperseed to form with the crystallization of the following scope of 100 nanometers more than 0.5 nanometer is disclosed.Yet this thermoelectric (al) inversion material is piled up or is scattered here and there owing to constitute the crystallization of thermoelectric (al) inversion material, thereby relative density reduces, thus the problem that causes performance to reduce.
With regard to the raising of pyroelectric material performance index, by above-mentioned ultra-micro powder is made the method for organizing miniaturization and importing impurity as raw material, affirmation can make conductive coefficient produce reducing to a certain degree.Tissue is made under the situation of fine crystal, the scattering of phonon increases, and can be used to reduce conductive coefficient.But the raising of actual performance is limited.Its reason is, has limitation on the manufacturing technology of ultramicron and sintering technology, can not make the sintered body with fine crystal tissue.In addition, the miniaturization of crystallization is accompanied by the increase than resistance usually, so performance index is increased.
Disclosure of an invention
Problem of the present invention is, solves the problem in the above-mentioned prior art, by reducing conductive coefficient under the situation of ratio resistance with the Min. increase that makes thermoelectric material, provides a kind of high performance thermoelectric material.
The thermoelectric material that the present invention relates to is that the average grain diameter of crystallization is in the following thermoelectric material of 50 nanometers, and the relative density of thermoelectric material is in more than 85%.
Wherein in the EDS of the grain boundary of thermoelectric material of the present invention part analyzes, the detected intensity of impurity element preferably is in below 1/5 of intensity of detected intensity maximum in the formation element of thermoelectric material.
And the ratio resistance of thermoelectric material of the present invention preferably is in 1X10
-3Below the Ω m.
The conductive coefficient of thermoelectric material of the present invention preferably is in below the 5W/mK.
The conductive coefficient of thermoelectric material of the present invention more preferably is in below the 1W/mK.
In addition, the manufacture method of the thermoelectric material that the present invention relates to, comprising the operation of making attritive powder and under the pressure more than the 1.0GPa, below the 10GPa with these attritive powder sintering or make the operation of its curing.
And in the manufacture method of thermoelectric material of the present invention, preferably include the operation of the polycrystal annealing with sintering or after solidifying.
Preferred forms
The inventor etc. are for solving found that above-mentioned problem furthers investigate, in a single day the average grain diameter that constitutes the crystallization of thermoelectric material is in below 50 nanometers, conductive coefficient will significantly reduce, and also can reduce corresponding to its increase of ratio resistance, find to reduce the inevitable impurity that exists at crystal boundary in addition and can reduce effectively and compare resistance.And then find a kind ofly to get the Control of Impurities that exists on the crystal boundary minimum and can access the manufacture method of fine crystal tissue, finished the present invention based on this.
That is to say that thermoelectric material of the present invention is characterized in that the average grain diameter of crystallization is in below 50 nanometers.Be controlled at below 50 nanometers by average grain diameter crystallization, can the acceleration of sintering body in the diffusion of phonon, conductive coefficient is suppressed low, improve the performance of thermoelectric material.Though the average grain diameter of crystallization is different because of material with correlation between the conductive coefficient of thermoelectric material, when the average grain diameter of crystallization is under the following situation of 50 nanometers, the reduction effect of conductive coefficient will become remarkable.By inference, this is because for the mean free path of phonon, fully reduces by the average grain diameter that makes crystallization, can promote the diffusion of phonon, thereby makes the cause of the conductive coefficient reduction of thermoelectric material.From the viewpoint that the conductive coefficient that makes thermoelectric material reduces, though the average grain diameter of crystallization is the smaller the better, the actual manufacturing limit of the minimum value of the average grain diameter of crystallization is about 0.001 micron.The average grain diameter of the thermoelectric material crystallization described in the application wherein is meant and the mean value of a plurality of crystallites (being considered as the small crystal of monocrystalline) size of the thermoelectric material crystal grain that formation can be confirmed with the through mode electron microscope specifically uses following method to obtain.That is to say, in the arbitrary site of the image that obtains with through mode electron microscope (TEM made in following brief note), draw a straight line that passes 50 crystallites, the length summation that is horizontally through crystallite in this straight line divided by the numerical value that crystallization several 50 obtains, is set at the average grain diameter of thermoelectric material crystallization.
And the relative density of thermoelectric material of the present invention preferably is in more than 85%, more preferably is in more than 90%.The relative density of thermoelectric material is lower than under 85% the situation, though the conductive coefficient of thermoelectric material has some reductions, but because of contact between the required crystallization of electrical conductivity reduces performance is reduced significantly.Relative density described here is meant that the volume from thermoelectric material behind the deduction gap is with respect to the ratio of all volumes of thermoelectric material.
In addition, in the thermoelectric material of the present invention, the detected intensity of impurity element was preferably during the EDS of the grain boundary portion of thermoelectric material analyzed, and thermoelectric material constitutes below 1/5 of intensity of detected intensity maximum in the element.Since by with the Control of Impurities of crystal boundary on low-level and can the ratio resistance inhibition of this thermoelectric material is low, so the performance of thermoelectric material is further improved.The impurity that is present in crystal boundary owing to have the diffusion that promotes phonon, makes the effect of the conductive coefficient reduction of thermoelectric material, so preferably there are some this impurity.Yet on the other hand, owing to also have the adverse effect that significantly hinders conductivity between the particle that constitutes crystal boundary, so denier preferably.Wherein the detected intensity of impurity element constitutes at thermoelectric material that detected intensity is in maximum below 1/5 of intensity in the element, also comprises grain boundary portion is carried out EDS when analyzing, and the impurity element amount is because below the mechanical detection limit and situation about not being detected.And described EDS analysis is meant the analysis of carrying out with the energy dispersion type x-ray analysis equipment.
In addition, in the thermoelectric material of the present invention, it preferably is in 1 * 10 than resistance
-3Below the Ω m.Rise than making above-mentioned performance index under the situation of resistance because reduce thermoelectric material.Simultaneously, the little performance index that also can improve thermoelectric material of the conductive coefficient of thermoelectric material is so the conductive coefficient of thermoelectric material of the present invention preferably is in below the 5W/mk.In addition, under the conductive coefficient of thermoelectric material of the present invention is in situation below the 1W/mK, more preferably from the performance index viewpoint that can further improve electricity generation material.Though the conductive coefficient of thermoelectric material is different numerical value such as kind, impurity content, crystalline texture because of thermoelectric material, in manufacture method of the present invention, can adjust in the above-mentioned scope (5W/mk is following or 1W/mk is following).
Thermoelectric material of the present invention can adopt comprising the production process of attritive powder with below the above 10GPa of 0.5GPa, preferably at the above 10GPa of 1.0GPa with under the downforce, with the attritive powder sintering or make the manufacture method manufacturing of the operation of its curing.
As the attritive powder that uses among the present invention, for example can using, average grain diameter is in the following particle of 50 nanometers.Because use average grain diameter to be under the situation of the following particle of 50 nanometers, the average grain diameter that can access a kind of crystallization is in the following thermoelectric material of 50 nanometers.
And attritive powder, wish to comprise average grain diameter be in the following crystallite of 50 nanometers in conjunction with set, particle diameter is in the offspring of 0.1 micron～100 microns sizes.Obtain under the situation of the such fine crystal tissue of thermoelectric material of the present invention because the particle diameter of necessary particle is very little, so active high, the surface of particle easily because of oxidation etc. by contaminating impurity.
And attritive powder preferably contains the particle that comprises dislocation.Comprise when particle under the situation of dislocation and defective, in sintering or curing process, perhaps in heat treatment step thereafter, can be that starting point produces crystallization again with dislocation and defective, thereby make thermoelectric material thermosetting micro crystal structure of the present invention.The particle that comprises dislocation described here is meant, comprises dislocation and defective, and the degree of crystallinity of measuring with X-ray diffraction is in the particle below 70%.
X ray total scattering intensity is said the interference capability intensity of having deducted Compton scattering exactly, and is irrelevant with noncrystal quantity ratio with crystal, will keep constant.Therefore, the degree of crystallinity of utilizing X-ray diffraction to obtain, for example can adopt the X ray scattering strength and ratio (%) of the crystal block section of the particle that will comprise dislocation as the X ray scattering strength of the particle of 100% crystal, perhaps will comprise dislocation particle noncrystal part the X ray scattering strength with deduct from 100 as the ratio (%) of the X ray scattering strength of 100% non-crystal particle after numerical value (%) obtain.
The attritive powder that the present invention adopts, can adopt mechanical crushing method such as ball mill, in a vacuum or the gas in the inert gas atmosphere send the technology manufacturing of method or heat plasma manufactured attritive powder forth.Mechanical crushing method for example is a method of utilizing the ball of ball mill and the motion shearing force between the tank body that particle is pulverized.In this method, in a single day particle diameter reduces, and because of being subjected to forming the offspring that crystallite is formed in conjunction with set from the pressure of ball and tank body, perhaps can making and produce dislocation and defective on the particle that constitutes attritive powder.Gas is sent method forth, compare with mechanical crushing methods such as ball mills, be a kind of method that can reduce impurity content, by making particle with the quenching of drop state, so can access fine and contain the particle of many defectives towards the particle blowing gas that is under the molten condition.And heat plasma attritive powder manufacturing process, be to make its quenching and condensation after utilizing high-temperature plasma with the attritive powder material gasification, obtain fine and contain a kind of method of the particle of many defectives.
By dislocation and the defective that these methods import, in sintering, will become the starting point of crystallization again, except that constituting micro organization, in sintered body, become the scattering source of phonon, have the effect of the conductive coefficient reduction that makes thermoelectric material.
In addition, below the above 10GPa of 0.5GPa, preferably at the above 10GPa of 1.0GPa with under the downforce, the attritive powder sintering that will prepare through said method or make its curing.This is with high-density sintered or make the cause of its curing for attritive powder is not produced excessive germination.With high-density sintered thermoelectric material, needed the shattering process of pressurization in order not make germination, and the densification process that slip and plastic flowing process etc. cause between particle.Be lower than under the pressure of 0.5GPa the attritive powder sintering or making under the situation of its curing, owing to do not carry out sliding process between the particle, so be difficult to obtain highdensity thermoelectric material.And be lower than under the pressure of 1.0GPa the attritive powder sintering or making under the situation of its curing, though it is also relevant with the shear strength of the particle that constitutes attritive powder, but do not carry out owing to constitute the shattering process of the particle of attritive powder, so the tendency that is difficult to obtain highdensity thermoelectric material is arranged.On the other hand, when under the pressure that is being higher than 10GPa with the attritive powder sintering or make under the situation of its curing, though can obtain the high density thermoelectric material under the situation that does not make germination, the cost when sintering or curing sharply rises, and the thermoelectric material volume that obtains is reduced.In addition, the sintering described in the present invention is meant, makes the phenomenon of two or more particle combinations because of heating.And the curing described in the present invention is meant, makes the phenomenon of two or more particle combinations because of the phenomenon beyond the sintering.
In addition, the sintering of attritive powder or the operation of curing, when preferably representing according to absolute temperature, minimum fusing point T1's (K) carries out under the temperature below 60% more than 25% in the fusing point of the material that constitutes attritive powder.The sintering of attritive powder or the temperature of curing process are lower than under 25% the situation of T1, and the sintering of attritive powder or be solidified with is difficult to the tendency of carrying out, and the sharply tendency of growth of particle are arranged in that the temperature higher than 60% temperature of T1 is next.
In the manufacture method of thermoelectric material of the present invention, preferably include behind the sintering or the operation of annealing of the polycrystal after solidifying.Discoveries such as the inventor, by under predetermined temperature to sintering after or solidify after polycrystal heat-treat (annealing), can be under the situation of control germination the performance of raising thermoelectric material.By carrying out annealing in process, can obtain to eliminate behind the sintering or solidify after polycrystal in the effect of crystal boundary distortion, simultaneously different with common annealing, can also obtain almost to can't see behind the sintering or the effect of germination in the polycrystal after solidifying.
Wherein said annealing, preferably the carrying out under the 65% following temperature more than 45% of minimum fusing point T2 (K) after constituting sintering or in the multicrystal material melting point after solidifying.Be lower than under the situation of annealing under 45% the temperature of above-mentioned fusing point T2, the tendency that is difficult to obtain eliminate the effect of crystal boundary distortion etc. is being arranged.And under the situation of annealing under than 65% of above-mentioned fusing point T2 high temperature, because of particle sharply growth the conductive coefficient of thermoelectric material is risen significantly, the tendency that has the performance that makes thermoelectric material to reduce.
And in the manufacture method of thermoelectric material of the present invention, the sintering of attritive powder production process and attritive powder or curing process preferably carry out in inert gas atmosphere or in the vacuum atmosphere.In this case, impurity is difficult to sneak among the thermoelectric material.
Below utilize embodiment that the specific embodiment of the present invention is described.
(embodiment 1)
Select raw material FeSi cheap and that obtain easily
2As thermoelectric material, verified effect of the present invention.With commercially available FeSi
2Powder (10～20 microns of particle diameters) is sealed in the iron flask with iron ball, become inert gas atmosphere with argon replaces after, pulverized 10 hours with planetary ball mill.Pulverize back FeSi
2The offspring particle diameter of powder is confirmed as 0.5～2 micron through the SEM observation.The size of crystallite is utilized FeSi
2It is 5～10 nanometers (the average grain diameter 8nm of crystallite) that the integral breadth of the XRD determining of powder is obtained (Hall method).And in Ar aura case with this FeSi
2Powder filling is enclosed in the nickel capsule, has carried out 30 minutes sintering under 3GPa pressure and 700 ℃.Confirm that through XRD determining sintered body is FeSi behind the sintering
2Single-phase.To the result of tissue of sintered body with tem observation, the average grain diameter that constitutes the crystallization of sintered body is 15 nanometers.And the relative density of sintered body is 93%.
Make the disk sample of 10 millimeters of diameters, 1 millimeter of thickness with this sintered body, utilize the laser flash method to measure conductive coefficient, the result is 0.98W/mK.
(reference examples 1)
Example 1 in contrast, directly adopts same powder, 200MPa and 1150 ℃ of following sintering 1 hour, then makes because of the abnormal high temperature of sintering turns back to the low temperature phase mutually, carried out 10 hours heat treatment under 800 ℃.Though this sintered body confirms it is FeSi through XRD determining
2Single-phase, but the conductive coefficient of the disk shaped samples made from this sintered body same as described above but is 10W/mK.
(embodiment 2)
Except the pulverizing time with ball mill was decided to be 5 hours, adopt the operation identical to make sintered body with embodiment 1, measured the average grain diameter and the conductive coefficient of the crystallization of formation sintered body.It the results are shown in the following table 1.Wherein in table 1, No.4 is the result of embodiment 2, and No.5 is embodiment 1 result.And the average grain diameter of the crystallite after the ball mill pulverizing is 35 nanometers.The presentation of results of table 1, the crystallization particle diameter of tissue of sintered body is in below 0.05 micron, and conductive coefficient significantly reduces.
(reference examples 2)
Except the pulverizing time with ball mill was decided to be respectively 0,1 and 2 hour, utilize the operation identical to make sintered body with embodiment 1, measured the average grain diameter and the conductive coefficient of the crystallization of formation sintered body.It the results are shown in the following table 1.Wherein in table 1, No.1 is decided to be 0 hour at the pulverizing time with ball mill, and No.2 is decided to be 1 hour, and No.3 is decided to be 2 hours.And the average grain diameter of the crystallite after the ball mill pulverizing is respectively (No.1) more than 5 microns, 0.9 micron (No.2) and 85 nanometers (No.3).
The result of table 1. embodiment 1～2 and reference examples 2
| No. | The ball milling time (hr) | The average grain diameter of sintered body (micron) | Conductive coefficient (W/mK) |
| 1 | 0 | 20 | 10 |
| 2 | 1 | 1 | 6.4 |
| 3 | 2 | 0.1 | 3.9 |
| 4 | 5 | 0.05 | 2.0 |
| 5 | 10 | 0.015 | 0.98 |
(embodiment 3)
Downcut the sample of 1mm * 1mm * 15mm size from the sintered body of embodiment 1 (No.5 of table 1), measured with four binding post methods and compared resistance.And the grain boundary portion of sintered body carried out the EDS analysis, identified the formation element.In addition, under the condition identical with No.5, (No.7) the two kinds of sintered bodies that prepared (No.6) that in the air of argon replaces of no use, has carried out ball milling and in atmosphere, carried out the filling operation of sintering forward direction Ni capsule.These samples and above-mentioned having carried out are equally analyzed than the mensuration and the EDS of resistance.The results are shown among the table 2.
These presentation of results, the impurity of crystal boundary (being oxide in this case) contrast resistance has a significant impact, and compares resistance even the fine crystal tissue also can reduce by minimizing impurity.
The result of table 2. embodiment 3
| No. | The ball milling time (hr) | Than resistance (Ω m) | The O peak intensity ※ of EDS |
| 5 | 10 | 9×10 -4 | 0.15 |
| 6 | 10 | 5×10 -3 | 0.30 |
| 7 | 10 | 1.5×10 -3 | 0.25 |
※ is decided to be the K α of the Si of main peak 1 o'clock relative intensity
(embodiment 4)
With fusion after Fe powder and the Si powder, send method forth with gas in a vacuum and made attritive powder.Used the strong helium of cooling performance when sending forth, air pressure has been transferred to double centner power/square centimeter.Particle diameter is 5～20 microns when utilizing SEM to observe this powder.And be 2～10 nanometers (average grain diameter 7 nanometers) through the crystallite size that XRD determining is obtained.
With this powder filling and sintering similarly to Example 1.With the sintered body that the obtains result with tem observation, the crystallization particle diameter of this sintered body is 5～20 nanometers (average grain diameter is 15 nanometers).And then after measuring the conductive coefficient of this sintered body similarly to Example 1, be 0.94W/mK.This explanation, it is the method that is suitable for making the sintered body with micro crystal structure equally that gas is sent method forth.
(reference examples 3)
Except under 0.2GPa and 700 ℃, carrying out 30 minutes sintering, make sintered body similarly to Example 1 after, obtained crisp and relative density is low to moderate 70% sintered body.Become 90% and the sintered body that obtained having certain intensity though sintering temperature is brought up to relative density after 1000 ℃, the crystal particle diameter of sintered body but becomes 0.1～2 micron, fails to obtain fine crystalline structure.After the conductive coefficient mensuration to same sintered body, being 5.9W/mK, is 8 * 10 than resistance
-4Ω m.Therefore, beyond sintering condition scope of the present invention, can not obtain to have the thermoelectric material of fine crystal tissue required for the present invention.
(embodiment 5)
The sintered body that embodiment 1 and embodiment 2 are obtained under the temperature of 670K (fusing point T2 45%), 800K (fusing point T2 54%) and 960K (fusing point T2 65%), has carried out annealing in 1 hour in argon gas atmosphere.The sintered body that the result anneals under 670K and 800K temperature, under the constant situation of conductive coefficient, conductivity is brought up to 1.3 times and 1.5 times respectively.The observed result of electron microscope confirms that the crystallization particle diameter of sintered body is constant before and after annealing.And the conductivity of the sintered body of annealing under the 960K temperature and conductive coefficient increase to 2 times and 1.5 times respectively.
With the sintered body that embodiment 1 and embodiment 2 obtain, under 600K in argon gas atmosphere (fusing point T2 41%) and 1030K (fusing point T2 the 70%) temperature, carried out annealing in 1 hour.600K is the sintered body of annealing down, and its conductive coefficient and conductivity all do not become, and do not find structural variation with electron microscope yet.On the other hand, the sintered body of under the 1030K temperature, annealing, conductivity reaches twice, and conductive coefficient is about 6W/mK, increase to six times (with respect to embodiment 1) with comparing from three times (with respect to embodiment 2) before the annealing, but performance index has reduced but.
(embodiment 6)
About FeSi
2Thermoelectric material has in addition also carried out the research same with embodiment 1～4.The results are shown in (No.8～19) in the following table 3.Wherein Seebeck coefficient is not owing to almost having correlation with particle diameter, so not record in table 3.The result shows, utilizes sintering condition of the present invention can obtain having the thermoelectric material of fine crystal tissue required for the present invention.And the average grain diameter of crystallization is below 50 nanometers, and relative density is at the thermoelectric material of the present invention more than 85%, and the conductive coefficient numerical value under relative ratio resistance and the room temperature (25 ℃) all has the trend of reduction.
The result of study of table 3. embodiment 6
| No . | Material system | The ball milling time (hr) | Sintering temperature (℃) | Sintering pressure (GPa) | The average grain diameter of sintered body (micron) | Relative density (%) | EDS impurity oxygen peak intensity ratio | Resistance (the ratio during with HP: doubly) compares | Room temperature conductive coefficient (W/mK) |
| 8 | ZnO | 4 | 900 | 1 | 0.05 | 89 | - | 1.00 | 10 |
| 9 | ZnO | 4 | 900 | 3 | 0.035 | 93 | - | 0.98 | 8 |
| 10 | ZnO | 4 | 820 | 5 | 0.023 | 96 | - | 1.03 | 4.8 |
| 11 | CoSb 3 | 10 | 600 | 1 | 0.050 | 85 | 0.03 | 0.98 | 4 |
| 12 | CoSb 3 | 10 | 600 | 3 | 0.030 | 90 | 0.03 | 0.95 | 3.5 |
| 13 | CoSb 3 | 10 | 500 | 10 | 0.025 | 98 | 0.04 | 0.87 | 3.1 |
| 14 | Zn 4Sb 3 | 8 | 250 | 2 | 0.010 | 100 | 0.01 | 1.00 | 0.36 |
| 15 | Zn 4Sb 3 | 8 | 250 | 5 | 0.010 | 100 | 0.01 | 1.02 | 0.35 |
| 16 | Mg 2Si | 4 | 400 | 3 | 0.020 | 100 | 0.08 | 0.95 | 1.4 |
| 17 | MnSi 1.75 | 4 | 400 | 3 | 0.020 | 100 | 0.05 | 0.97 | 1.6 |
| 18 | ZrNiSn | 10 | 700 | 5 | 0.027 | 100 | 0.03 | 0.98 | 4.7 |
| 19 | ZrNiSn | 10 | 700 | 10 | 0.010 | 100 | 0.03 | 1.05 | 3.8 |
(reference examples 4)
About FeSi
2Thermoelectric material has in addition been made sintered body, and has been studied equally with embodiment 1～4 under the condition shown in the following note table 4 different with embodiment 6.The results are shown in (No.20～37) among the table 4.Just as shown in table 4, in the reference examples of under the condition different, making 4 with embodiment 6, the average grain diameter that does not obtain any one crystallization below 50 nanometers, relative density is at the sintered body more than 85%.And the sintered body of reference examples 4 (No.20～37) compares with the sintered body (No.8～19) of embodiment 6, and the tendency of minimizing is arranged than resistance and all good number of room temperature conductive coefficient.
The result of study of table 4. reference examples 4
| No. | Material system | The ball milling time (hr) | Sintering temperature (℃) | Sintering pressure (GPa) | The average grain diameter of sintered body (micron) | Relative density (%) | EDS impurity oxygen peak intensity ratio | Resistance (the ratio during with HP: doubly) compares | Room temperature conductive coefficient (W/mK) |
| 20 | ZnO | 4 | 1400 | 0.1 | 5 | 82 | - | 1.00 | 42 |
| 21 | ZnO | 4 | 1300 | 0.8 | 1.5 | 84 | - | 1.00 | 30 |
| 22 | ZnO | 4 | 750 | 0.5 | - | Sintering not | - | - | - |
| 23 | ZnO | 4 | 850 | 0.5 | 0.02 | 73 | - | 32.00 | 18 |
| 24 | ZnO | 4 | 850 | 0.1 | 0.04 | 66 | - | 126.00 | 7 |
| 25 | ZnO | 4 | 1050 | 0.5 | 0.07 | 80 | - | 15.00 | 20 |
| 26 | ZnO | 4 | 1100 | 0.8 | 0.09 | 86 | - | 5.70 | 25 |
| 27 | CoSb 3 | 10 | 800 | Atmospheric pressure | - | Sintering not | 0.03 | - | - |
| 28 | CoSb 3 | 10 | 800 | 0.1 | 1.4 | 90 | 0.03 | 1.00 | 7.5 |
| 29 | CoSb 3 | 10 | 800 | 0.3 | 1.2 | 92 | 0.04 | 0.91 | 7 |
| 30 | CoSb 3 | 10 | 650 | 0.9 | 0.075 | 85 | 0.04 | 3.20 | 7 |
| 31 | CoSb 3 | 10 | 600 | 0.9 | 0.045 | 77 | 0.03 | 10.30 | 4.5 |
| 32 | CoSb 3 | 10 | 600 | 0.8 | 0.05 | 78 | 0.04 | 14.50 | 5.5 |
| 33 | Zn 4Sb 3 | 8 | 500 | 0.1 | 1 | 97 | ＜0.01 | 1.00 | 0.7 |
| 34 | Mg 2Si | 4 | 600 | 0.1 | 1 | 98 | 0.08 | 1.00 | 2.3 |
| 35 | MnSi 1.75 | 4 | 600 | 0.1 | 1 | 97 | 0.05 | 1.00 | 3.2 |
| 36 | ZrNiSn | 10 | 850 | 0.1 | 1.2 | 97 | 0.03 | 1.00 | 10 |
| 37 | ZrNiSn | 10 | 850 | 0.5 | 0.9 | 98 | 0.03 | 1.02 | 9 |
Wherein in table 3 and table 4, the expression of material system constitutes the composition of the material of thermoelectric material, and the ZnO of table 3 and table 4 (No.8～10, No.20～26) has used the material of the 2 atom %Al that mixed in Zn.
And EDS impurity oxygen peak intensity is than the ratio of expression with respect to the sample of the detected intensity maximum of utilizing the EDS analysis to obtain.In addition, be under the situation of ZnO (No.8～10, No.20～26) at material, because oxygen is not impurity, so the impurity oxygen peak intensity that EDS draws is than being "-".
And the numerical value of the resistance that compares, use with respect to the ratio value representation that carries out numerical value under hot pressing (HP) the sintering situation under the 0.1GPa pressure.The numerical value of resistance of comparing is to represent to reduce than resistance under the situation below 1.0.
The possibility of using on the industry
As mentioned above, the manufacture method of thermoelectric material of the present invention and thermoelectric material of the present invention, can make than resistance increases minimum, and thermal conductivity factor is reduced, and improves thermoelectricity capability.
In addition, also can use beyond the material that the present invention enumerates in an embodiment, can help to improve the performance of existing thermoelectric material.
Claims (8)
1. a thermoelectric material is that the average grain diameter of crystallization is in the thermoelectric material that 10 nanometers are above and 50 nanometers are following, it is characterized in that the relative density of described thermoelectric material is in more than 85%,
Wherein said thermoelectric material is iron suicide, zinc oxide, antimony cobalt, zinc antimonide, magnesium silicide, silication manganese or zirconium nickel tin.
2. according to the described thermoelectric material of claim 1, in the EDS of the grain boundary of described thermoelectric material part analyzed, the detected intensity of impurity element was in below 1/5 of intensity of detected intensity maximum in the formation element of described thermoelectric material.
3. according to the described thermoelectric material of claim 1, it is characterized in that being in 9 * 10 than resistance
-4Ω m is above and 1 * 10
-3Below the Ω m.
4. according to the described thermoelectric material of claim 1, it is characterized in that conductive coefficient is in below the 5W/mK.
5. according to the described thermoelectric material of claim 1, it is characterized in that conductive coefficient is in below the 1W/mK.
6. the manufacture method of a thermoelectric material, comprising the operation of making attritive powder and under the pressure more than the 1.0GPa and below the 10GPa with described attritive powder sintering or make the operation of its curing.
7. according to the manufacture method of the described thermoelectric material of claim 6, it is characterized in that comprising operation with the annealing of the polycrystal after described sintering or the described curing.
8. according to the manufacture method of the described thermoelectric material of claim 6, it is characterized in that described attritive powder is to adopt gas to send method or ball milling manufacturing forth.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002344763 | 2002-11-28 | ||
| JP344763/2002 | 2002-11-28 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1717814A CN1717814A (en) | 2006-01-04 |
| CN100459201C true CN100459201C (en) | 2009-02-04 |
Family
ID=32375967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB2003801043786A Expired - Fee Related CN100459201C (en) | 2002-11-28 | 2003-11-27 | Thermoelectric material and method for producing same |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US20060053969A1 (en) |
| JP (1) | JP4569298B2 (en) |
| KR (1) | KR100924054B1 (en) |
| CN (1) | CN100459201C (en) |
| AU (1) | AU2003284476A1 (en) |
| WO (1) | WO2004049464A1 (en) |
Families Citing this family (35)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4497981B2 (en) * | 2004-03-30 | 2010-07-07 | 株式会社東芝 | Thermoelectric material and thermoelectric conversion element |
| US8865995B2 (en) * | 2004-10-29 | 2014-10-21 | Trustees Of Boston College | Methods for high figure-of-merit in nanostructured thermoelectric materials |
| US7465871B2 (en) * | 2004-10-29 | 2008-12-16 | Massachusetts Institute Of Technology | Nanocomposites with high thermoelectric figures of merit |
| FR2884353B1 (en) | 2005-04-06 | 2007-07-13 | Centre Nat Rech Scient | PRODUCTION OF THERMOELECTRIC MATERIALS BY MECANOSYNTHESIS |
| JP5249212B2 (en) * | 2006-06-26 | 2013-07-31 | ダイヤモンド イノベーションズ、インク． | Increase in Seebeck coefficient of semiconductors by high pressure / high temperature sintering |
| US8058092B2 (en) * | 2007-09-28 | 2011-11-15 | Stion Corporation | Method and material for processing iron disilicide for photovoltaic application |
| US8614396B2 (en) * | 2007-09-28 | 2013-12-24 | Stion Corporation | Method and material for purifying iron disilicide for photovoltaic application |
| US8440903B1 (en) | 2008-02-21 | 2013-05-14 | Stion Corporation | Method and structure for forming module using a powder coating and thermal treatment process |
| US8772078B1 (en) | 2008-03-03 | 2014-07-08 | Stion Corporation | Method and system for laser separation for exclusion region of multi-junction photovoltaic materials |
| US8075723B1 (en) | 2008-03-03 | 2011-12-13 | Stion Corporation | Laser separation method for manufacture of unit cells for thin film photovoltaic materials |
| US8883047B2 (en) * | 2008-04-30 | 2014-11-11 | Massachusetts Institute Of Technology | Thermoelectric skutterudite compositions and methods for producing the same |
| US7939454B1 (en) | 2008-05-31 | 2011-05-10 | Stion Corporation | Module and lamination process for multijunction cells |
| US8207008B1 (en) | 2008-08-01 | 2012-06-26 | Stion Corporation | Affixing method and solar decal device using a thin film photovoltaic |
| KR101534372B1 (en) * | 2009-01-09 | 2015-07-07 | 다이아몬드 이노베이션즈, 인크. | Affecting the thermoelectric figure of merit (zt) by high pressure, high temperature sintering |
| JP2010206024A (en) * | 2009-03-04 | 2010-09-16 | Yanmar Co Ltd | Thermoelectric module, and manufacturing method of thermoelectric module |
| CN101549405A (en) * | 2009-05-19 | 2009-10-07 | 燕山大学 | High-pressure sintering preparation method of high-densification high-performance nano crystal block thermoelectric material |
| US9123856B2 (en) * | 2010-03-11 | 2015-09-01 | Diamond Innovations, Inc. | Affecting the thermoelectric figure of merit (ZT) and the power factor by high pressure, high temperature sintering |
| US10751801B2 (en) * | 2013-11-22 | 2020-08-25 | The Government Of The United States Of America, As Represented By The Secretary Of The Navy | Bulk monolithic nano-heterostructures and method of making the same |
| JP2012023201A (en) * | 2010-07-14 | 2012-02-02 | Toyota Motor Corp | Manufacturing method of thermoelectric conversion material |
| WO2012087931A2 (en) * | 2010-12-20 | 2012-06-28 | Trustees Of Boston College | Half-heusler alloys with enhanced figure of merit and methods of making |
| US9048004B2 (en) | 2010-12-20 | 2015-06-02 | Gmz Energy, Inc. | Half-heusler alloys with enhanced figure of merit and methods of making |
| CN102383023B (en) * | 2011-11-08 | 2013-06-05 | 天津大学 | Preparation method for ferro-silico-manganese alloy thermoelectric material |
| CN104205382A (en) | 2012-01-25 | 2014-12-10 | 阿尔法贝特能源公司 | Modular thermoelectric units for heat recovery systems and methods thereof |
| WO2013141065A1 (en) * | 2012-03-21 | 2013-09-26 | リンテック株式会社 | Thermoelectric conversion material and method for manufacturing same |
| US9257627B2 (en) | 2012-07-23 | 2016-02-09 | Alphabet Energy, Inc. | Method and structure for thermoelectric unicouple assembly |
| DE102013213334A1 (en) * | 2013-07-08 | 2015-01-08 | Deutsches Zentrum für Luft- und Raumfahrt e.V. | Production of skutterudite |
| US9065017B2 (en) | 2013-09-01 | 2015-06-23 | Alphabet Energy, Inc. | Thermoelectric devices having reduced thermal stress and contact resistance, and methods of forming and using the same |
| JP2014220506A (en) * | 2014-06-17 | 2014-11-20 | ダイヤモンドイノベイションズ インコーポレーテッド | Effect of thermoelectric figure of merit (zt) by high pressure and high temperature sintering |
| CN104022218A (en) * | 2014-06-23 | 2014-09-03 | 武汉理工大学 | High-performance SbAgSeS-based thermoelectric material and preparation method thereof |
| CN105355771B (en) * | 2015-10-16 | 2018-09-28 | 中国科学院上海硅酸盐研究所 | A kind of high power factor zinc oxide thermoelectric material and preparation method thereof |
| WO2017146095A1 (en) * | 2016-02-24 | 2017-08-31 | 三菱マテリアル株式会社 | Method for manufacturing magnesium-based thermoelectric conversion material, method for manufacturing magnesium-based thermoelectric conversion element, magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and thermoelectric conversion device |
| JP6991973B2 (en) | 2016-07-28 | 2022-01-13 | 株式会社東芝 | Thermoelectric materials, manufacturing methods of thermoelectric materials, thermoelectric conversion elements, and thermoelectric conversion modules |
| JP6617840B2 (en) * | 2017-01-20 | 2019-12-11 | 日立金属株式会社 | P-type thermoelectric conversion material, thermoelectric conversion module, and method for producing p-type thermoelectric conversion material |
| KR102490113B1 (en) | 2018-06-12 | 2023-01-17 | 주식회사 케이티 | Apparatus and Method for broadcasting disaster |
| US11963448B2 (en) | 2020-03-23 | 2024-04-16 | Proterial, Ltd. | Method for producing thermoelectric conversion element |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6043424A (en) * | 1996-07-03 | 2000-03-28 | Yamaha Corporation | Thermoelectric alloy achieving large figure of merit by reducing oxide and process of manufacturing thereof |
| CN1252625A (en) * | 1998-10-12 | 2000-05-10 | 株式会社小松制作所 | Thermoelectric semiconductor material or device and its producing method and apparatus |
| JP2000307158A (en) * | 1999-04-19 | 2000-11-02 | Yamaha Corp | Manufacture of thermoelectric material |
| US6307143B1 (en) * | 1998-10-22 | 2001-10-23 | Yamaha Corporation | Thermoelectric materials and thermoelectric conversion element |
| US20020026856A1 (en) * | 2000-09-04 | 2002-03-07 | Akiko Suzuki | Thermoelectric material and method of manufacturing the same |
| CN1359162A (en) * | 2000-11-30 | 2002-07-17 | 雅马哈株式会社 | Quality factor omproved thermoelectric material, its making method and assembly using same |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06237018A (en) * | 1993-02-09 | 1994-08-23 | Onoda Cement Co Ltd | Manufacture of thermoelectric conversion |
| JPH10209508A (en) * | 1997-01-22 | 1998-08-07 | Toshiba Corp | Thermoelectric transducer and its manufacture |
| EP0874406A3 (en) * | 1997-04-23 | 2000-12-13 | Matsushita Electric Industrial Co., Ltd. | A co-sb based thermoelectric material and a method of producing the same |
| JPH10303468A (en) * | 1997-04-23 | 1998-11-13 | Matsushita Electric Ind Co Ltd | Thermoelectric material and its manufacture |
| JP3958857B2 (en) * | 1998-03-13 | 2007-08-15 | 株式会社小松製作所 | Thermoelectric semiconductor material manufacturing method |
| JPH11284237A (en) * | 1998-03-31 | 1999-10-15 | Matsushita Electric Works Ltd | Manufacture of p-type thermoelectric conversion material |
| CA2331533A1 (en) * | 1999-03-10 | 2000-09-14 | Osamu Yamashita | Thermoelectric conversion material and method of producing the same |
| JP3580778B2 (en) * | 2001-01-29 | 2004-10-27 | 京セラ株式会社 | Thermoelectric conversion element and method of manufacturing the same |
-
2003
- 2003-11-27 AU AU2003284476A patent/AU2003284476A1/en not_active Abandoned
- 2003-11-27 CN CNB2003801043786A patent/CN100459201C/en not_active Expired - Fee Related
- 2003-11-27 US US10/536,879 patent/US20060053969A1/en not_active Abandoned
- 2003-11-27 WO PCT/JP2003/015194 patent/WO2004049464A1/en active Application Filing
- 2003-11-27 JP JP2004555069A patent/JP4569298B2/en not_active Expired - Fee Related
- 2003-11-27 KR KR1020057009595A patent/KR100924054B1/en not_active IP Right Cessation
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6043424A (en) * | 1996-07-03 | 2000-03-28 | Yamaha Corporation | Thermoelectric alloy achieving large figure of merit by reducing oxide and process of manufacturing thereof |
| CN1252625A (en) * | 1998-10-12 | 2000-05-10 | 株式会社小松制作所 | Thermoelectric semiconductor material or device and its producing method and apparatus |
| US6307143B1 (en) * | 1998-10-22 | 2001-10-23 | Yamaha Corporation | Thermoelectric materials and thermoelectric conversion element |
| JP2000307158A (en) * | 1999-04-19 | 2000-11-02 | Yamaha Corp | Manufacture of thermoelectric material |
| US20020026856A1 (en) * | 2000-09-04 | 2002-03-07 | Akiko Suzuki | Thermoelectric material and method of manufacturing the same |
| CN1359162A (en) * | 2000-11-30 | 2002-07-17 | 雅马哈株式会社 | Quality factor omproved thermoelectric material, its making method and assembly using same |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2004049464A1 (en) | 2004-06-10 |
| AU2003284476A1 (en) | 2004-06-18 |
| US20060053969A1 (en) | 2006-03-16 |
| KR100924054B1 (en) | 2009-10-27 |
| JP4569298B2 (en) | 2010-10-27 |
| KR20050085179A (en) | 2005-08-29 |
| JPWO2004049464A1 (en) | 2006-03-30 |
| CN1717814A (en) | 2006-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN100459201C (en) | Thermoelectric material and method for producing same | |
| US8865995B2 (en) | Methods for high figure-of-merit in nanostructured thermoelectric materials | |
| Bux et al. | Nanostructured bulk silicon as an effective thermoelectric material | |
| KR100398939B1 (en) | Thermoelectric transducing material | |
| KR20090110831A (en) | Methods for high figure-of-merit in nanostructured thermoelectric materials | |
| CN102714269B (en) | Process for producing nanocomposite thermoelectric conversion material | |
| Trivedi et al. | Microstructure and doping effect on the enhancement of the thermoelectric properties of Ni doped Dy filled CoSb 3 skutterudites | |
| CN101549405A (en) | High-pressure sintering preparation method of high-densification high-performance nano crystal block thermoelectric material | |
| US9306145B2 (en) | Methods of synthesizing thermoelectric materials | |
| EP2528856A2 (en) | Nanocomposites with high thermoelectric performance and methods | |
| CN103314458A (en) | Half-heusler alloys with enhanced figure of merit and methods of making | |
| JP2016529699A (en) | Thermoelectric materials based on tetrahedral copper ore structure for thermoelectric elements | |
| US8883047B2 (en) | Thermoelectric skutterudite compositions and methods for producing the same | |
| CN102694116A (en) | Method for preparing thermoelectric material with P-type nano-structure and bismuth telluride matrix | |
| JP4374578B2 (en) | Thermoelectric material and manufacturing method thereof | |
| JP4504523B2 (en) | Thermoelectric material and manufacturing method thereof | |
| KR20070117270A (en) | Method for fabricating thermoelectric material by mechanical milling-mixing and thermoelectric material fabricated thereby | |
| WO2018212297A1 (en) | Semiconductor sintered compact, electric/electronic member, and method for producing semiconductor sintered compact | |
| KR101405318B1 (en) | Bismuth telluride-indium selenide nanocomposite thermoelectric materials and method of manufacturing the same | |
| US5458867A (en) | Process for the chemical preparation of bismuth telluride | |
| JP4459400B2 (en) | Thermoelectric material and manufacturing method thereof | |
| KR101469759B1 (en) | Manufacturing method for Fe-Sb thermoelectric material doped with Yb | |
| US20180233647A1 (en) | Formation of P-Type Filled Skutterudite by Ball-Milling and Thermo-Mechanical Processing | |
| JPH10102160A (en) | Production of cobalt triantimonide type composite material | |
| KR102560464B1 (en) | Method for synthesizing Sn-doped Magnesium-Antimonide thermoelectric materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090204 Termination date: 20101127 |