Fabrication of Mg2Si thermal-to-electric energy conversion device using die-casting sysnthesis method

压铸合成法制造Mg2Si热电能量转换装置

基本信息

批准号：
17360130
负责人：
TAKANASHI Yoshifumi
金额：
$ 9.7万
依托单位：
Tokyo University of Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

Magnesium siliside (Mg2Si) crystals have been grown using the vertical Bridgman method in a non-wetting growth environment, achieved by the use of an anti-adhesion coating on the crucible wall. The minimized adhesion of highly reactive molten magnesium (Mg), silicon (Si) and Mg2Si permitted easy removal of the grown ingot from the crucible, and the external shape of the grown ingot followed the shape of inner wall of the crucible. The grown crystals were a single phase of polycrystalline Mg2Si. The grown crystals exhibited n-type conductivity, which could result from the residual impurities in the Mg source material used and unintentional impurity incorporation during growth. Since Mg2Si is a material candidate for thermal-to-electric energy-conversion, the thermoelectric properties such as Seebeck coefficient, electrical conductivity, and thermal conductivity, were measured as a function of temperature up to 873K. Die-casting process induced characteristics of such thermoelectric prop … More erties are discussed. The maximum dimensionless figure-of-merit was estimated to be 0.17 at 656K. Electrode materials consisting of Cu, Ti and Ni were formed on Bi-doped n-type Mg2Si by means of a monobloc plasma-activated sintering (PAS) technique. Due to the difference in thermal expansion coefficients between Ti and Mg2Si, rather high residual thermal stresses gave rise to the introduction of cracks, which were mainly located in the Mg2Si layer, when Ti was used as the electrode material. In the case of the Cu electrodes, monobloc sintering could not be performed in a reproducible manner because Cu melts abruptly and effuses at around 973K, which is 100K lower than the sintering temperature that is required for Mg2Si of good crystalline quality. When compared with the results for Cu and Ti, the monobloc PAS process for Ni was both stable and reproducible. The room-temperature I-V characteristics of Ni electrodes were considered to be adequate for practical applications, with durable Mg2Si-electrode junction properties being realized at a practical operating temperature of 600K with delta-T=500K. Less

硅化镁 (Mg2Si) 晶体是在非润湿生长环境中采用垂直布里奇曼法生长的，通过在坩埚壁上使用防粘附涂层，最大限度地减少高反应性熔融镁 (Mg)、硅的粘附。 (Si)和Mg 2 Si使得生长的锭能够容易地从坩埚中取出，并且生长的锭的外部形状遵循坩埚内壁的形状。生长的晶体是多晶 Mg2Si 的单相。生长的晶体表现出 n 型导电性，这可能是由于所使用的 Mg 源材料中残留的杂质以及生长过程中无意掺入的杂质造成的。在高达 873K 的压铸过程中，测量了热电性能（例如塞贝克系数、电导率和热导率）与温度的函数关系。讨论了这种热电特性的感应特性。在 656K 时，最大无量纲品质因数估计为 0.17。通过 Bi 掺杂的 n 型 Mg2Si 形成了由 Cu、Ti 和 Ni 组成的电极材料。整体等离子体激活烧结（PAS）技术由于Ti和Mg2Si之间的热膨胀系数不同，相当高的残余热应力导致裂纹的产生。主要位于 Mg2Si 层中，当 Ti 用作 Cu 电极时，由于 Cu 在 973K 左右突然熔化并流出，因此无法以可重复的方式进行整体烧结，该温度比 973K 低 100K。良好结晶质量的 Mg2Si 所需的烧结温度与 Cu 和 Ti 的结果相比，Ni 的整体 PAS 工艺既稳定又可靠。 Ni 电极的室温 I-V 特性被认为足以满足实际应用的需要，在 600K 的实际工作温度（δT=500K）下实现了耐用的 Mg2Si 电极结性能。

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Thermoelectric properties of undoped p-type CoSb_3 prepared by the vertical Bridgman crystal growth and the spark plasma sintering

垂直布里奇曼晶体生长和放电等离子体烧结制备的未掺杂p型CoSb_3的热电性能

DOI：
发表时间：
2006
期刊：
Journal of Alloys and Compounds 415
影响因子：
0
作者：
M. Akasaka;T. Iida;J. Soga;N. Kato;T. Sakuma;Y. Higuchi;Y. Takanashi;M. Akasaka;M. Fukano;T.Nemoto;T.Sakuma;S.Furuyama
通讯作者：
S.Furuyama

Fabrication of Mg2Si from a Reused-silicon Source and its Thermoelectric Characteristics

再生硅源制备Mg2Si及其热电特性

DOI：
发表时间：
期刊：
Thermoelectric Power Generation (Mater. Res. Soc. Proc. Vol. 1044), ed. by T. P. Hogan, J. Yang, R. Funahashi, T. Tritt, (Mater. Res. Soc., 2008)
影响因子：
0
作者：
M. Akasaka;T. Iida;Y. Mito;T. Omori;Y. Oguni;S. Yokoyama;K. Nishio;Y. Takanashi
通讯作者：
Y. Takanashi

The thermoelectric properties of bulk crystals of n-, p-type Mg_2Si prepared by the vertical Bridgman method

立式布里奇曼法制备n型、p型Mg_2Si块状晶体的热电性能

DOI：
发表时间：
2008
期刊：
Journal of Applied Physics 104
影响因子：
0
作者：
T. Matsushita;K. Nakajima;M. Suzuki;K. Kimura;A. Agarwal;H.-J. Gossmann;M. Ameen;M. Akasaka
通讯作者：
M. Akasaka

熱電変換材料およびその製造方法

热电转换材料及其制造方法