JP2011249742A - Magnesium-silicon based thermoelectric conversion material and method of producing the same - Google Patents
Magnesium-silicon based thermoelectric conversion material and method of producing the same Download PDFInfo
- Publication number
- JP2011249742A JP2011249742A JP2010136571A JP2010136571A JP2011249742A JP 2011249742 A JP2011249742 A JP 2011249742A JP 2010136571 A JP2010136571 A JP 2010136571A JP 2010136571 A JP2010136571 A JP 2010136571A JP 2011249742 A JP2011249742 A JP 2011249742A
- Authority
- JP
- Japan
- Prior art keywords
- metal
- magnesium
- thermoelectric conversion
- conversion material
- silicon
- 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.)
- Granted
Links
Images
Abstract
Description
本発明は、マグネシウム−シリコン系熱電変換材料およびその製造方法に関し、特に、マグネシウムシリサイド（Ｍｇ２Ｓｉ）のマトリックス中に少なくともＭｇＯ相が分散した複合材料およびその製造方法に関するものである。The present invention relates to a magnesium-silicon thermoelectric conversion material and a method for producing the same, and more particularly to a composite material in which at least a MgO phase is dispersed in a matrix of magnesium silicide (Mg 2 Si) and a method for producing the same.
現在、排熱回収によるエネルギーの有効利用が注目されている。その中で熱電変換材料を用いた熱電変換素子を用い、排熱により発電し、電気エネルギーとして回収する方法が提案されている。熱電変換材料としては、従来よりＢｉ−Ｔｅ系、Ｃｏ−Ｓｂ系、Ｚｎ−Ｓｂ系、Ｐｂ−Ｔｅ系、Ａｇ−Ｓｂ−Ｇｅ−Ｔｅ系等が約２００〜８００℃の排熱を利用する用途で開発、一部実用化されている。しかしながら、これらの熱電変換材料に使用する元素は毒性やコストの面で様々な問題を有している。そのため、Ｍｇ２Ｓｉ等シリサイド系の熱電変換材料は、毒性がないこと、資源が豊富で安価であることから、その活用が検討されている。At present, the effective use of energy by exhaust heat recovery is attracting attention. Among them, a method has been proposed in which a thermoelectric conversion element using a thermoelectric conversion material is used to generate power by exhaust heat and recover it as electric energy. As thermoelectric conversion materials, Bi-Te series, Co-Sb series, Zn-Sb series, Pb-Te series, Ag-Sb-Ge-Te series and the like that use exhaust heat of about 200 to 800 ° C have been used. Developed and partially put into practical use. However, the elements used in these thermoelectric conversion materials have various problems in terms of toxicity and cost. For this reason, utilization of silicide-based thermoelectric conversion materials such as Mg 2 Si has been studied because they are not toxic and are abundant and inexpensive.
Ｍｇ２Ｓｉの融点は１０８５℃であるところ、Ｍｇの沸点は１０９７℃であり、ＭｇとＳｉを溶解してＭｇ２Ｓｉを作製する場合、Ｍｇの蒸発が問題となる。そこで従来より、Ｍｇの融点以上に加熱し、Ｓｉ粉末と反応させる固相−液相反応を用い、Ｍｇ２Ｓｉ粉末を得る方法が研究されている。（特許文献１、２）The melting point of Mg 2 Si is 1085 ° C., but the boiling point of Mg is 1097 ° C. When Mg 2 Si is produced by dissolving Mg and Si, the evaporation of Mg becomes a problem. Therefore, conventionally, a method for obtaining Mg 2 Si powder by using a solid-liquid phase reaction in which it is heated above the melting point of Mg and reacted with Si powder has been studied. (Patent Documents 1 and 2)
しかしながら、特許文献１および２で開示された製造方法によると、得られるＭｇ２Ｓｉは粉末状となり、さらに焼結工程が必要になるか、塊状で得られても熱電変換素子として使用に耐える十分な密度および強度を有していない。However, according to the manufacturing methods disclosed in Patent Documents 1 and 2, the obtained Mg 2 Si is in a powder form, and further requires a sintering process, or is sufficient to withstand use as a thermoelectric conversion element even if obtained in a lump form. Does not have the proper density and strength.
本発明の課題は、高い密度および強度を有するマグネシウム−シリコン系熱電変換材料を提供することにある。
本発明の別の課題は、本発明のマグネシウム−シリコン系熱電変換材料の製造に適した効率的な製造方法を提供することにある。An object of the present invention is to provide a magnesium-silicon based thermoelectric conversion material having high density and strength.
Another subject of this invention is providing the efficient manufacturing method suitable for manufacture of the magnesium-silicon type thermoelectric conversion material of this invention.
また本発明によれば、原料として少なくとも金属Ｍｇと金属ＳｉとＳｉＯ２を使用し、これらを混合した状態で、真空もしくは不活性雰囲気中、４５０〜１０００℃で熱処理するマグネシウム−シリコン系熱電変換材料の製造方法が提供される。
さらに本発明によれば、Ｃｕ−Ｋα線をＸ線源とするＸ線回折測定において、ＭｇＯ相に起因する２θ＝４２．０°〜４４．０°の範囲に現れる最強ピーク強度（Ｉａ）とＭｇ２Ｓｉ相に起因する２θ＝３９．０°〜４１．０°の範囲に現れる最強ピーク強度（Ｉｂ）との強度比（Ｉａ／Ｉｂ）が０．６以下（０を含まない）であるマグネシウム−シリコン系熱電変換材料が提供される。Further, according to the present invention, at least metal Mg, metal Si, and SiO 2 are used as raw materials, and the magnesium-silicon thermoelectric conversion material is heat-treated at 450 to 1000 ° C. in a vacuum or an inert atmosphere in a mixed state. A manufacturing method is provided.
Furthermore, according to the present invention, in the X-ray diffraction measurement using Cu—Kα rays as an X-ray source, the strongest peak intensity (Ia) appearing in the range of 2θ = 42.0 ° to 44.0 ° due to the MgO phase The intensity ratio (Ia / Ib) to the strongest peak intensity (Ib) appearing in the range of 2θ = 39.0 ° to 41.0 ° due to the Mg 2 Si phase is 0.6 or less (not including 0) A magnesium-silicon thermoelectric conversion material is provided.
本発明のマグネシウム−シリコン系熱電変換材料は高い密度および強度を有する。本発明のマグネシウム−シリコン系熱電変換材料の製造方法は、本発明のマグネシウム−シリコン系熱電変換材料の製造に適した効率的な製造方法であって、Ｍｇ２Ｓｉの合成と同時に密度の大きいマグネシウム−シリコン系熱電変換材料を得ることができる。The magnesium-silicon based thermoelectric conversion material of the present invention has high density and strength. The method for producing a magnesium-silicon thermoelectric conversion material of the present invention is an efficient production method suitable for the production of the magnesium-silicon thermoelectric conversion material of the present invention, and magnesium having a high density simultaneously with the synthesis of Mg 2 Si. -A silicon-based thermoelectric conversion material can be obtained.
本発明のマグネシウム−シリコン系熱電変換材料の製造方法は、原料として少なくとも金属Ｍｇと金属ＳｉとＳｉＯ２を使用し、これらを混合した状態で、真空もしくは不活性雰囲気中、４５０〜１０００℃で熱処理する。４５０℃以上に加熱することにより金属Ｍｇは金属Ｓｉと反応し、Ｍｇ２Ｓｉを生成する。また、金属ＭｇはＳｉＯ２を還元し、自身は酸化され、金属ＳｉとＭｇＯを生成する。還元されて生成した金属Ｓｉも金属Ｍｇと反応しＭｇ２Ｓｉを生成する。ＳｉＯ２と金属Ｍｇの反応を利用することで、生成するＭｇ２ＳｉとＭｇＯの粒子間に強固な結合が生じることから、密度および強度の高いマグネシウム−シリコン系熱電変換材料を得ることができる。金属Ｍｇの蒸発を防ぐためには、なるべく低い温度で熱処理を行うことが好ましいが、十分に反応を進行するために５００〜７５０℃程度で行うことが好ましい。未反応の金属Ｍｇが残留すると耐酸化性が著しく低下する。熱処理時間は通常１分〜３時間程度で行う。The method for producing a magnesium-silicon thermoelectric conversion material of the present invention uses at least metal Mg, metal Si, and SiO 2 as raw materials, and heat treatment at 450 to 1000 ° C. in a vacuum or an inert atmosphere in a mixed state. To do. When heated to 450 ° C. or higher, the metal Mg reacts with the metal Si to produce Mg 2 Si. Further, the metal Mg reduces SiO 2 and oxidizes itself to generate metal Si and MgO. Metal Si produced by reduction also reacts with metal Mg to produce Mg 2 Si. By utilizing the reaction of SiO 2 and metal Mg, a strong bond is generated between the generated particles of Mg 2 Si and MgO, so that a magnesium-silicon thermoelectric conversion material with high density and strength can be obtained. In order to prevent the metal Mg from evaporating, it is preferable to perform the heat treatment at a temperature as low as possible, but it is preferable to perform the heat treatment at about 500 to 750 ° C. in order to sufficiently proceed the reaction. If unreacted metal Mg remains, the oxidation resistance is significantly reduced. The heat treatment time is usually about 1 minute to 3 hours.
金属Ｍｇは酸化しやすいため、熱処理を行う雰囲気は真空または不活性雰囲気で行うことが好ましい。さらに好ましくは不活性雰囲気で加圧した雰囲気にする。この場合、金属Ｍｇの酸化を防ぐと同時に蒸発も抑制できる。 Since metal Mg is easily oxidized, it is preferable that the atmosphere for the heat treatment be a vacuum or an inert atmosphere. More preferably, the atmosphere is pressurized in an inert atmosphere. In this case, evaporation of metal Mg can be prevented and at the same time evaporation can be suppressed.
金属Ｍｇと金属Ｓｉ、ＳｉＯ２の反応は、いわゆる液相−固相反応で進行する。したがって、金属Ｍｇと金属Ｓｉ、ＳｉＯ２は密に接触した状態であることが好ましい。さらに好ましくは予めボールミル等を使用して均一な混合状態としておく。また、原料を混合した後、プレス成形を行い、原料の密度を高くしておくことも有効である。金属Ｍｇ、金属Ｓｉ、ＳｉＯ２は粉末形態のものを用いることが好ましい。また、生成するＭｇＯ相は原料のＳｉＯ２の形態を継承する。得られるマグネシウム−シリコン系熱電変換材料中のＭｇＯ相の粒径が小さく、分散している場合、電子伝導率を低下させることなく、熱伝導率を小さくできる傾向にある。したがって、原料に使用するＳｉＯ２の平均粉末粒径は可能な限り小さい方が好ましく、工業生産上は０．１〜１００μｍであることが好ましい。さらに好ましくは０．１〜１０μｍである。一方、生成するＭｇ２Ｓｉ相は、主に原料の金属Ｓｉの形態を承継する。Ｍｇ２Ｓｉ相の粒径は小さい方が熱伝導率を小さくできる傾向にある。したがって原料に使用する金属Ｓｉの平均粉末粒径は可能な限り小さい方が好ましく、工業生産上は０．１〜５０μｍであることが好ましい。さらに好ましくは０．１〜１０μｍである。ここでの平均粉末粒径とは、ＳＥＭによる観察像でランダムに選択した粉末の最長径とその最長径に垂直な線分で定められる短径との平均値を算出し、５０個以上について同様にして算出した値の平均値とした。The reaction between metal Mg, metal Si, and SiO 2 proceeds by a so-called liquid-solid reaction. Therefore, it is preferable that the metal Mg and the metal Si, SiO 2 are in close contact with each other. More preferably, a uniform mixing state is previously obtained using a ball mill or the like. It is also effective to perform press molding after mixing the raw materials to increase the density of the raw materials. Metal Mg, metal Si, and SiO 2 are preferably used in powder form. The generated MgO phase inherits the form of the raw material SiO 2 . When the particle diameter of the MgO phase in the obtained magnesium-silicon-based thermoelectric conversion material is small and dispersed, the thermal conductivity tends to be reduced without decreasing the electronic conductivity. Therefore, the average powder particle diameter of SiO 2 used for the raw material is preferably as small as possible, and is preferably 0.1 to 100 μm for industrial production. More preferably, it is 0.1-10 micrometers. On the other hand, the resulting Mg 2 Si phase, mainly succeed the form of a metal Si raw material. The smaller the particle size of the Mg 2 Si phase, the smaller the thermal conductivity tends to be. Therefore, the average powder particle size of the metal Si used as a raw material is preferably as small as possible, and is preferably 0.1 to 50 μm for industrial production. More preferably, it is 0.1-10 micrometers. The average powder particle size here is the average value of the longest diameter of the powder randomly selected from the observation image by SEM and the short diameter defined by the line segment perpendicular to the longest diameter. It was set as the average of the values calculated in this way.
原料に使用する金属Ｍｇ、金属Ｓｉ、ＳｉＯ２の純度は高い方が好ましい。通常は９９．９％以上の純度のものが使用できる。また、ｎ型またはｐ型の特性を改善するため、ドーパントとしてＢ、Ａｌ、Ｇａ、Ｉｎ、Ｐ、Ａｓ、Ｓｂ、Ｂｉ、Ｌｉ、Ｎａ、Ｋ、Ａｇ、Ｃｕ、等から選択される少なくとも１種の元素を添加することができる。当然ながらドーパントもなるべく高純度の原料を使用することが好ましく、その添加量は通常５原子％以下である。The purity of metal Mg, metal Si, and SiO 2 used for the raw material is preferably higher. Usually, the purity of 99.9% or more can be used. In order to improve the n-type or p-type characteristics, at least one dopant selected from B, Al, Ga, In, P, As, Sb, Bi, Li, Na, K, Ag, Cu, etc. is used as a dopant. These elements can be added. Of course, it is preferable to use as high a purity raw material as possible for the dopant, and the addition amount is usually 5 atomic% or less.
熱処理は、雰囲気制御が可能な通常の熱処理炉で行うことができる。金属Ｍｇの蒸発を抑制し、金属Ｍｇと金属ＳｉおよびＳｉＯ２との反応を進行させ、密度および強度の高いマグネシウム−シリコン系熱電変換材料を得るために、炉内を大気圧以上に加圧して行うことが好ましい。さらに好ましくは、ホットプレス法、熱間等方圧プレス法（ＨＩＰ）、放電プラズマ焼結法（ＳＰＳ）、熱間圧延法、熱間押出法等加圧もしくは塑性加工を行いながら熱処理する。これらの方法で行うと、前述したＳｉＯ２の反応を利用した効果とあいまって、密度および強度の高いマグネシウム−シリコン系熱電変換材料を得ることができる。The heat treatment can be performed in a normal heat treatment furnace capable of controlling the atmosphere. In order to suppress the evaporation of metal Mg, advance the reaction of metal Mg with metal Si and SiO 2, and obtain a magnesium-silicon thermoelectric conversion material with high density and strength, the inside of the furnace was pressurized above atmospheric pressure. Preferably it is done. More preferably, heat treatment is performed while performing pressurization or plastic working such as hot pressing, hot isostatic pressing (HIP), spark plasma sintering (SPS), hot rolling, hot extrusion or the like. When these methods are used, a magnesium-silicon thermoelectric conversion material having a high density and strength can be obtained in combination with the above-described effect of utilizing the reaction of SiO 2 .
原料の金属ＳｉとＳｉＯ２の混合比は、（金属Ｓｉのモル数）／（ＳｉＯ２のモル数）が１以上であることが好ましい。さらに好ましくは混合比が２以上、最も好ましくは３以上である。混合比を１以上とすることで生成するＭｇＯ相または残留するＳｉＯ２の量を適当な範囲に制御することで、熱電特性と強度を有するマグネシウム−シリコン系熱電変換材料が得られる。The mixing ratio of the raw material metal Si and SiO 2 is preferably such that (number of moles of metal Si) / (number of moles of SiO 2 ) is 1 or more. More preferably, the mixing ratio is 2 or more, and most preferably 3 or more. A magnesium-silicon thermoelectric conversion material having thermoelectric characteristics and strength can be obtained by controlling the amount of MgO phase produced or residual SiO 2 by adjusting the mixing ratio to 1 or more within an appropriate range.
原料の金属Ｍｇと金属ＳｉおよびＳｉＯ２の混合比は、（金属Ｍｇのモル数）／（（金属Ｓｉのモル数）＋２×（ＳｉＯ２のモル数））が１．８〜２．２であることが好ましい。熱処理時に溶融した金属ＭｇとＳｉＯ２との反応は、２Ｍｇ＋ＳｉＯ２→２ＭｇＯ＋Ｓｉである。したがって、ＳｉＯ２１モルの還元に金属Ｍｇは２モル消費される。この混合比が２．０の場合、原料中のＭｇとＳｉ（金属ＳｉおよびＳｉＯ２中のＳｉの合計量）がすべてＭｇ２Ｓｉの合成に消費される場合の理論量である。この場合、金属Ｍｇが残留しにくいため好ましい。ただし、金属Ｍｇの蒸発を完全に抑えることは困難であるため、予め蒸発量に相当する金属Ｍｇを増量しておくことが好ましい。したがって、この混合比は、２．０〜２．２の間で適宜調整することが最も好ましい。The mixing ratio of the raw material metal Mg, metal Si and SiO 2 is (metal Mg mole number) / ((metal Si mole number) + 2 × (SiO 2 mole number)) is 1.8 to 2.2. Preferably there is. The reaction between the metal Mg melted during the heat treatment and SiO 2 is 2Mg + SiO 2 → 2MgO + Si. Therefore, 2 mol of metal Mg is consumed for reducing 1 mol of SiO 2 . When the mixing ratio is 2.0, this is a theoretical amount when all of Mg and Si (total amount of metal Si and Si in SiO 2 ) in the raw material are consumed for the synthesis of Mg 2 Si. In this case, metal Mg is preferable because it does not easily remain. However, since it is difficult to completely suppress the evaporation of metal Mg, it is preferable to increase the amount of metal Mg corresponding to the evaporation amount in advance. Therefore, this mixing ratio is most preferably adjusted appropriately between 2.0 and 2.2.
本発明のマグネシウム−シリコン系熱電変換材料は、Ｃｕ−Ｋα線をＸ線源とするＸ線回折測定において、ＭｇＯ相に起因する２θ＝４２．０°〜４４．０°の範囲に現れる最強ピーク強度（Ｉａ）とＭｇ２Ｓｉ相に起因する２θ＝３９．０°〜４１．０°の範囲に現れる最強ピーク強度（Ｉｂ）との強度比（Ｉａ／Ｉｂ）が０．６以下（０を含まない）である。本発明のマグネシウム−シリコン系熱電変換材料は、Ｍｇ２Ｓｉ相を主相とし、副相として少なくともＭｇＯ相を含有する。Ｉａ／Ｉｂが０．６以下の場合、熱電特性と強度を両立できる。Ｉａ／Ｉｂは、０．２以下であることが好ましく、さらに好ましくは０．１以下である。The magnesium-silicon thermoelectric conversion material of the present invention has the strongest peak that appears in the range of 2θ = 42.0 ° to 44.0 ° due to the MgO phase in X-ray diffraction measurement using Cu—Kα rays as an X-ray source. The intensity ratio (Ia / Ib) between the intensity (Ia) and the strongest peak intensity (Ib) appearing in the range of 2θ = 39.0 ° to 41.0 ° due to the Mg 2 Si phase is 0.6 or less (0 Not included). The magnesium-silicon-based thermoelectric conversion material of the present invention contains an Mg 2 Si phase as a main phase and at least an MgO phase as a sub phase. When Ia / Ib is 0.6 or less, both thermoelectric characteristics and strength can be achieved. Ia / Ib is preferably 0.2 or less, and more preferably 0.1 or less.
前述の通り、マグネシウム−シリコン系熱電変換材料中のＭｇＯ相の粒径が小さく、分散している場合、電子伝導率を低下させることなく、熱伝導率を小さくできる傾向にある。したがって、本発明のマグネシウム−シリコン系熱電変換材料中のＭｇＯ相の平均粒径は可能な限り小さい方が好ましく、工業生産上は０．１〜１００μｍであることが好ましい。さらに好ましくは０．１〜１０μｍである。また、マグネシウム−シリコン系熱電変換材料中のＭｇ２Ｓｉ相の粒径は小さい方が熱伝導率を小さくできる傾向にある。したがって、本発明のマグネシウム−シリコン系熱電変換材料中のＭｇ２Ｓｉ相の平均粒径は可能な限り小さい方が好ましく、工業生産上は０．１〜５０μｍであることが好ましい。さらに好ましくは０．１〜１０μｍである。ここでの平均粒径とは、ＥＰＭＡでＭｇＯ相、Ｍｇ２Ｓｉ相を確認後、ＳＥＭによる観察像でランダムに選択したＭｇＯ相、Ｍｇ２Ｓｉ相の最長径とその最長径に垂直な線分で定められる短径との平均値を算出し、５０個以上について同様にして算出した値の平均値とした。As described above, when the particle diameter of the MgO phase in the magnesium-silicon-based thermoelectric conversion material is small and dispersed, the thermal conductivity tends to be reduced without reducing the electronic conductivity. Therefore, the average particle diameter of the MgO phase in the magnesium-silicon thermoelectric conversion material of the present invention is preferably as small as possible, and is preferably 0.1 to 100 μm for industrial production. More preferably, it is 0.1-10 micrometers. Moreover, the smaller the particle size of the Mg 2 Si phase in the magnesium-silicon based thermoelectric conversion material, the smaller the thermal conductivity tends to be. Therefore, the average particle size of the Mg 2 Si phase in the magnesium-silicon thermoelectric conversion material of the present invention is preferably as small as possible, and is preferably 0.1 to 50 μm for industrial production. More preferably, it is 0.1-10 micrometers. The average particle size here, MgO phase EPMA, after checking the Mg 2 Si phase, randomly selected MgO phase observation image by SEM, the largest diameter perpendicular line to the longest diameter of the Mg 2 Si phase The average value with the minor axis determined in (1) was calculated, and the average value of the values calculated in the same manner for 50 or more.
前述の通り、本発明のマグネシウム−シリコン系熱電変換材料はｎ型またはｐ型の特性を改善するため、ドーパントとしてＢ、Ａｌ、Ｇａ、Ｉｎ、Ｐ、Ａｓ、Ｓｂ、Ｂｉ、Ｌｉ、Ｎａ、Ｋ、Ａｇ、Ｃｕ、等から選択される少なくとも１種の元素を含有することができる。その含有量は通常５原子％以下である。 As described above, the magnesium-silicon-based thermoelectric conversion material of the present invention improves the n-type or p-type characteristics, so that B, Al, Ga, In, P, As, Sb, Bi, Li, Na, K are used as dopants. And at least one element selected from Ag, Cu, and the like. Its content is usually 5 atomic% or less.
以下、実施例及び比較例により本発明を詳細に説明するが、本発明はこれらに限定されない。
実施例１
原料として、金属Ｍｇ粉末（平均粉末粒径１２５μｍ）、金属Ｓｉ粉末（平均粉末粒径４３μｍ）、ＳｉＯ２粉末（平均粉末粒径４９μｍ）をそれぞれ２．６２ｇ（０．１０８ｍｏｌ）、０．５１ｇ（０．０１８ｍｏｌ）、１．０８ｇ（０．０１８ｍｏｌ）（（金属Ｓｉのモル数）／（ＳｉＯ２のモル数）＝１、（金属Ｍｇのモル数）／（（金属Ｓｉのモル数）＋２×（ＳｉＯ２のモル数））＝２）秤量し、乳鉢にて５分間混合した。混合した原料をΦ２０のダイスに入れて、１０ｔの圧力でプレスし、ペレット形状とした。得られたペレットを熱処理炉にてアルゴン雰囲気下、７００℃で１時間熱処理した。その後室温まで炉冷し、ペレットを回収した。ペレットはＭｇ２Ｓｉに特有の青紫色であった。ペレットをマイクロカッターで切断して、ペレットの断面をＣｕ−Ｋα線をＸ線源に使用し、Ｘ線解回折測定を行ったところＭｇ２ＳｉとＭｇＯの回折パターンによく一致した。ＭｇＯ相に起因する２θ＝４２．０°〜４４．０°の範囲に現れる最強ピーク強度（Ｉａ）とＭｇ２Ｓｉ相に起因する２θ＝３９．０°〜４１．０°の範囲に現れる最強ピーク強度（Ｉｂ）との強度比（Ｉａ／Ｉｂ）は、０．５３であった。
次いで、ペレットの断面をＥＰＭＡにて観察した。図１〜５に、それぞれ１００倍のＳＥＭ像、１０００倍のＳＥＭ像、Ｍｇのマッピング像、Ｓｉのマッピング像、酸素のマッピング像を示した。これらから、Ｍｇ２Ｓｉ相をマトリックスとし、ＭｇＯ相が存在する組織を有することがわかった。ＭｇＯ相の形状は、原料のＳｉＯ２粉末と同様であった。ＳＥＭ像よりランダムに５０個のＭｇＯ相とＭｇ２Ｓｉ相をそれぞれ選択し、平均結晶粒径を測定したところ、ＭｇＯ相は５３μｍ、Ｍｇ２Ｓｉ相は４３μｍであった。また、ペレットの断面をＳＥＭで観察した際のボイドの量を◎（なし）、○（少ない）、△（多い）の三段階で評価したところ○であった。EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to these.
Example 1
As raw materials, metal Mg powder (average powder particle size 125 μm), metal Si powder (average powder particle size 43 μm), and SiO 2 powder (average powder particle size 49 μm) were 2.62 g (0.108 mol) and 0.51 g (0 .018 mol), 1.08 g (0.018 mol) ((number of moles of metal Si) / (number of moles of SiO 2) = 1, (number of moles of metal Mg) / ((number of moles of metal Si) + 2 × (SiO 2 )) = 2) Weighed and mixed for 5 minutes in a mortar. The mixed raw material was put into a Φ20 die and pressed at a pressure of 10 t to form a pellet. The obtained pellets were heat-treated at 700 ° C. for 1 hour in an argon atmosphere in a heat treatment furnace. Thereafter, the furnace was cooled to room temperature, and the pellets were collected. The pellets were a bluish violet color characteristic of Mg 2 Si. The pellet was cut with a microcutter, and when the cross section of the pellet was subjected to X-ray diffraction analysis using Cu-Kα rays as an X-ray source, it was in good agreement with the diffraction patterns of Mg 2 Si and MgO. Strongest peak intensity (Ia) appearing in the range of 2θ = 42.0 ° to 44.0 ° due to the MgO phase and strongest appearing in the range of 2θ = 39.0 ° to 41.0 ° due to the Mg 2 Si phase The intensity ratio (Ia / Ib) to the peak intensity (Ib) was 0.53.
Subsequently, the cross section of the pellet was observed with EPMA. 1 to 5 show a 100 times SEM image, a 1000 times SEM image, a Mg mapping image, a Si mapping image, and an oxygen mapping image, respectively. From these, it was found that the Mg 2 Si phase was used as a matrix and the MgO phase was present. The shape of the MgO phase was the same as that of the raw material SiO 2 powder. From the SEM image, 50 MgO phases and Mg 2 Si phases were selected at random, and the average crystal grain size was measured. As a result, the MgO phase was 53 μm and the Mg 2 Si phase was 43 μm. In addition, when the cross section of the pellet was observed with an SEM, the amount of void was evaluated in three stages: ◎ (none), ○ (small), and Δ (large).
実施例２〜４
原料の金属Ｍｇ粉末、金属Ｓｉ粉末、ＳｉＯ２粉末の配合を表１のように変更した以外は実施例１と同様にして行った。結果を表１に示した。図６〜１０に、それぞれ実施例３で熱処理後に回収したペレットの断面の１００倍のＳＥＭ像、１０００倍のＳＥＭ像、Ｍｇのマッピング像、Ｓｉのマッピング像、酸素のマッピング像を示した。Examples 2-4
The same procedure as in Example 1 was performed except that the composition of the raw material metal Mg powder, metal Si powder, and SiO 2 powder was changed as shown in Table 1. The results are shown in Table 1. 6 to 10 show a 100-fold SEM image, a 1000-fold SEM image, a Mg mapping image, a Si mapping image, and an oxygen mapping image, respectively, of the cross section of the pellet recovered after the heat treatment in Example 3.
実施例５
原料として、金属Ｓｉ粉末（平均粉末粒径２μｍ）、ＳｉＯ２粉末（平均粉末粒径３μｍ）を使用し、ペレットをホットプレスにてアルゴン雰囲気下、１０ＭＰａの圧力で７００℃、３０分間熱処理した以外は、実施例１と同様にして行った。結果を表１に示す。Example 5
Metal Si powder (average powder particle size 2 μm) and SiO 2 powder (average powder particle size 3 μm) were used as raw materials, and the pellets were heat-treated at 700 ° C. for 30 minutes at 10 MPa pressure in an argon atmosphere by hot pressing. Was carried out in the same manner as in Example 1. The results are shown in Table 1.
比較例１
原料として、ＳｉＯ２粉末を用いず、金属Ｍｇ粉末、金属Ｓｉ粉末の配合を表１のように変更した以外は実施例１と同様にして行った。熱処理後、ペレットは粉末化した。
結果を表１に示す。
比較例２
原料の金属Ｍｇ粉末、金属Ｓｉ粉末、ＳｉＯ２粉末の配合を表１のように変更した以外は実施例１と同様にして行った。結果を表１に示した。Comparative Example 1
As the raw material, SiO 2 powder was not used, and the same procedure as in Example 1 was performed except that the composition of metal Mg powder and metal Si powder was changed as shown in Table 1. After the heat treatment, the pellets were pulverized.
The results are shown in Table 1.
Comparative Example 2
The same procedure as in Example 1 was performed except that the composition of the raw material metal Mg powder, metal Si powder, and SiO 2 powder was changed as shown in Table 1. The results are shown in Table 1.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010136571A JP5598792B2 (en) | 2010-05-28 | 2010-05-28 | Magnesium-silicon thermoelectric conversion material and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010136571A JP5598792B2 (en) | 2010-05-28 | 2010-05-28 | Magnesium-silicon thermoelectric conversion material and method for producing the same |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2011249742A true JP2011249742A (en) | 2011-12-08 |
| JP2011249742A5 JP2011249742A5 (en) | 2013-08-08 |
| JP5598792B2 JP5598792B2 (en) | 2014-10-01 |
Family
ID=45414588
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010136571A Active JP5598792B2 (en) | 2010-05-28 | 2010-05-28 | Magnesium-silicon thermoelectric conversion material and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5598792B2 (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102583391A (en) * | 2012-01-19 | 2012-07-18 | 太原理工大学 | Preparation method of high-purity nano-powder Mg2-xSiTMx thermoelectric materials |
| JP2013197550A (en) * | 2012-03-22 | 2013-09-30 | Ngk Insulators Ltd | Thermoelectric material and method for manufacturing the same |
| 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 |
| JP2017152691A (en) * | 2016-02-24 | 2017-08-31 | 三菱マテリアル株式会社 | Method of manufacturing magnesium-based thermoelectric conversion material, method of manufacturing magnesium-based thermoelectric conversion element, magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and thermoelectric converter |
| WO2017164217A1 (en) | 2016-03-24 | 2017-09-28 | 三菱マテリアル株式会社 | Thermoelectric conversion module |
| KR20180125962A (en) | 2016-03-24 | 2018-11-26 | 미쓰비시 마테리알 가부시키가이샤 | Thermoelectric conversion module |
| WO2019035253A1 (en) | 2017-08-15 | 2019-02-21 | 三菱マテリアル株式会社 | Magnesium thermoelectric conversion material, magnesium thermoelectric conversion element, and method for producing magnesium thermoelectric conversion material |
| JP2019068037A (en) * | 2017-05-19 | 2019-04-25 | 日東電工株式会社 | Semiconductor sintered body, electric/electronic member, and method for manufacturing semiconductor sintered body |
| JP2019149545A (en) * | 2018-02-27 | 2019-09-05 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element, thermoelectric conversion module, and manufacturing method of thermoelectric conversion material |
| WO2020137205A1 (en) * | 2018-12-26 | 2020-07-02 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element and thermoelectric conversion module |
| JPWO2019039320A1 (en) * | 2017-08-22 | 2020-12-24 | 株式会社白山 | Thermoelectric materials and thermoelectric modules |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003069001A1 (en) * | 2002-02-15 | 2003-08-21 | Toudai Tlo, Ltd. | Magnesium base composite material and method for production thereof |
| JP2004359995A (en) * | 2003-06-03 | 2004-12-24 | Toudai Tlo Ltd | Magnesium-alloy sliding member |
| JP2005325441A (en) * | 2001-09-25 | 2005-11-24 | Toudai Tlo Ltd | Magnesium-base composite material, green compact for production of magnesium-base composite material, and equipment for production of green compact |
| JP2008147261A (en) * | 2006-12-06 | 2008-06-26 | Toyota Industries Corp | P-type thermoelectric material, and its manufacturing method |
-
2010
- 2010-05-28 JP JP2010136571A patent/JP5598792B2/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005325441A (en) * | 2001-09-25 | 2005-11-24 | Toudai Tlo Ltd | Magnesium-base composite material, green compact for production of magnesium-base composite material, and equipment for production of green compact |
| WO2003069001A1 (en) * | 2002-02-15 | 2003-08-21 | Toudai Tlo, Ltd. | Magnesium base composite material and method for production thereof |
| JP2004359995A (en) * | 2003-06-03 | 2004-12-24 | Toudai Tlo Ltd | Magnesium-alloy sliding member |
| JP2008147261A (en) * | 2006-12-06 | 2008-06-26 | Toyota Industries Corp | P-type thermoelectric material, and its manufacturing method |
Cited By (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102583391A (en) * | 2012-01-19 | 2012-07-18 | 太原理工大学 | Preparation method of high-purity nano-powder Mg2-xSiTMx thermoelectric materials |
| CN102583391B (en) * | 2012-01-19 | 2013-10-30 | 太原理工大学 | Preparation method of high-purity nano-powder Mg2-xSiTMx thermoelectric materials |
| JP2013197550A (en) * | 2012-03-22 | 2013-09-30 | Ngk Insulators Ltd | Thermoelectric material and method for manufacturing the same |
| CN108701749B (en) * | 2016-02-24 | 2022-02-01 | 三菱综合材料株式会社 | Method for producing magnesium-based thermoelectric conversion material, method for producing magnesium-based thermoelectric conversion element, magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and thermoelectric conversion device |
| US10468577B2 (en) | 2016-02-24 | 2019-11-05 | Mitsubishi Materials Corporation | 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 |
| CN108701749A (en) * | 2016-02-24 | 2018-10-23 | 三菱综合材料株式会社 | The manufacturing method of magnesium system thermo-electric converting material, the manufacturing method of magnesium system thermoelectric conversion element, magnesium system thermo-electric converting material, magnesium system thermoelectric conversion element and thermoelectric conversion device |
| JP2017152691A (en) * | 2016-02-24 | 2017-08-31 | 三菱マテリアル株式会社 | Method of manufacturing magnesium-based thermoelectric conversion material, method of manufacturing magnesium-based thermoelectric conversion element, magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and thermoelectric converter |
| 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 |
| EP3422428A4 (en) * | 2016-02-24 | 2019-11-06 | Mitsubishi Materials Corporation | 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 |
| WO2017164217A1 (en) | 2016-03-24 | 2017-09-28 | 三菱マテリアル株式会社 | Thermoelectric conversion module |
| KR20180125962A (en) | 2016-03-24 | 2018-11-26 | 미쓰비시 마테리알 가부시키가이샤 | Thermoelectric conversion module |
| US10897001B2 (en) | 2016-03-24 | 2021-01-19 | Mitsubishi Materials Corporation | Thermoelectric conversion module |
| US11404620B2 (en) | 2017-05-19 | 2022-08-02 | Nitto Denko Corporation | Method of producing semiconductor sintered body, electrical/electronic member, and semiconductor sintered body |
| JP2019068037A (en) * | 2017-05-19 | 2019-04-25 | 日東電工株式会社 | Semiconductor sintered body, electric/electronic member, and method for manufacturing semiconductor sintered body |
| JP2019068038A (en) * | 2017-05-19 | 2019-04-25 | 日東電工株式会社 | Semiconductor sintered body, electric/electronic member, and method for manufacturing semiconductor sintered body |
| JP2019064899A (en) * | 2017-05-19 | 2019-04-25 | 日東電工株式会社 | Semiconductor sintered body, electrical and electronic member, and method for producing semiconductor sintered body |
| US11508893B2 (en) | 2017-05-19 | 2022-11-22 | Nitto Denko Corporation | Method of producing semiconductor sintered body |
| US11616182B2 (en) | 2017-05-19 | 2023-03-28 | Nitto Denko Corporation | Method of producing semiconductor sintered body, electrical/electronic member, and semiconductor sintered body |
| JP7137963B2 (en) | 2017-05-19 | 2022-09-15 | 日東電工株式会社 | Semiconductor sintered body, electric/electronic member, and method for manufacturing semiconductor sintered body |
| WO2019035253A1 (en) | 2017-08-15 | 2019-02-21 | 三菱マテリアル株式会社 | Magnesium thermoelectric conversion material, magnesium thermoelectric conversion element, and method for producing magnesium thermoelectric conversion material |
| JP2019036623A (en) * | 2017-08-15 | 2019-03-07 | 三菱マテリアル株式会社 | Magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and, manufacturing method of magnesium-based thermoelectric conversion material |
| US11462671B2 (en) | 2017-08-15 | 2022-10-04 | Mitsubishi Materials Corporation | Magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and method for producing magnesium-based thermoelectric conversion material |
| KR20200040751A (en) | 2017-08-15 | 2020-04-20 | 미쓰비시 마테리알 가부시키가이샤 | Magnesium-based thermoelectric conversion material, magnesium-based thermoelectric conversion element, and manufacturing method of magnesium-based thermoelectric conversion material |
| JPWO2019039320A1 (en) * | 2017-08-22 | 2020-12-24 | 株式会社白山 | Thermoelectric materials and thermoelectric modules |
| JP7228844B2 (en) | 2017-08-22 | 2023-02-27 | 株式会社白山 | Thermoelectric materials and thermoelectric modules |
| JP7251187B2 (en) | 2018-02-27 | 2023-04-04 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element, thermoelectric conversion module, and method for producing thermoelectric conversion material |
| JP2019149545A (en) * | 2018-02-27 | 2019-09-05 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element, thermoelectric conversion module, and manufacturing method of thermoelectric conversion material |
| WO2020137205A1 (en) * | 2018-12-26 | 2020-07-02 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element and thermoelectric conversion module |
| JP7159854B2 (en) | 2018-12-26 | 2022-10-25 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element, and thermoelectric conversion module |
| JP2020107650A (en) * | 2018-12-26 | 2020-07-09 | 三菱マテリアル株式会社 | Thermoelectric conversion material, thermoelectric conversion element and thermoelectric conversion module |
Also Published As
| Publication number | Publication date |
|---|---|
| JP5598792B2 (en) | 2014-10-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5598792B2 (en) | Magnesium-silicon thermoelectric conversion material and method for producing the same | |
| US9634219B2 (en) | Method for producing a thermoelectric object for a thermoelectric conversion device | |
| JP2013138166A (en) | Method for forming multi-element electro-thermal alloy | |
| JP2012190984A (en) | Magnesium silicide powder, sintered compact and thermoelectric conversion element using the same, and method for producing the same | |
| US20120114517A1 (en) | Thermoelectric material formed of Mg2Si-based compound and production method therefor | |
| US20160190421A1 (en) | Method for producing a thermoelectric object for a thermoelectric conversion device | |
| JP2008159680A (en) | Yb-ae-fe-co-sb (ae:ca, sr, ba, cu, ag, au)-based thermoelectric conversion material | |
| US20120138843A1 (en) | Mechanochemical synthesis and thermoelectric properties of magnesium silicide and related alloys | |
| CN102383023A (en) | Preparation method for ferro-silico-manganese alloy thermoelectric material | |
| JP2006086512A (en) | Thermoelectric conversion system using filled skutterudite alloy | |
| JP7448259B2 (en) | Thermoelectric materials, their manufacturing methods, and thermoelectric power generation elements | |
| US20180269369A1 (en) | Thermoelectric conversion material | |
| JP2012256759A (en) | Clathrate compound and thermoelectric conversion material and production method of thermoelectric conversion material | |
| Zhang et al. | Energy-Efficient Synthesis and Superior Thermoelectric Performance of Sb-doped Mg2Si0. 3Sn0. 7 Solid Solutions by Rapid Thermal Explosion | |
| JP4123388B2 (en) | Zinc antimony compound sintered compact | |
| JP5090939B2 (en) | p-type thermoelectric conversion material | |
| JP2004075467A (en) | Boron suboxide powder and method for producing sintered compact thereof | |
| JP5482229B2 (en) | Thermoelectric material and manufacturing method thereof | |
| JP7159635B2 (en) | Silicide-based alloy material and element using the same | |
| Pengfei et al. | High temperature dephosphorus behavior of Baotou mixed rare earth concentrate with carbon | |
| JP4373296B2 (en) | Raw material for thermoelectric conversion material, method for producing thermoelectric conversion material, and thermoelectric conversion material | |
| JP2665014B2 (en) | Manufacturing method of thermoelectric conversion element material | |
| JP6155141B2 (en) | Thermoelectric conversion material and method for producing the same | |
| JP3704556B2 (en) | Method for producing zinc antimony compound | |
| JP5653654B2 (en) | Method for manufacturing thermoelectric material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20130508 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130513 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140424 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140513 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140528 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140722 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140801 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5598792 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |