Development of Low-Temperature Processes for High-Temperature Intermetallic Compounds and their microstructure control

高温金属间化合物低温工艺开发及其微观结构控制

• 批准号: 07555228
• 负责人: MARUYAMA Toshio
• 金额: $ 3.9万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07555228/
• 关键词: Mo(Si, Al)_2; Nb(Si, Al)_2; Nb(Al, Si)_3; intermetallic compounds; hot dipping; self-propagation; liquid-phase reactive sintering; 低温合成; 高温酸化; 表面コーティング

(1) DIP COATING OF Nb BY USING Al-Si LIQUIDBy dipping of Nb in Si-saturated Al liquid at temperatures from 940 K to 1140 K,C40-type Nb(Si_<0.9>, Al_<0.1>)_2 layr formed at the interface on Nb. The intermetallic layr consisted of fine particles with submicrons in diameter and included Al-Si liquid between particles. The growth of Nb(Si, Al)_2 layr was rate-controlled by the dissolution-precipitation reaction at the Nb/Nb(Si, Al)_2 interface. The growth rate of Nb(Si, Al)_2 was 3 times faster than that of Mo(Si, Al)_2 in the Mo dipping.In the dipping of Nb in non-saturated Al-Si liquid at 1025 K,C40-type Nb(Si, Al)_2 formed with Al-23 mol% Si liquid. The growth rate was faster than that in the case of the saturated Al-Si liquid. Product layr by dipping Nb in Al-Si liquid with around 20 mol% Si exhibited the layr-by-layr structure consisting of C40-type Nb(Si, Al)_2 and D0_<22>-type Nb(Al, Si)_3. With decreasing Si content down to 5 mol% in Al-Si liquid, the product layr consisted of the … More D0_<22>-type Nb(Al, Si)_3. Their results imply that C54-type Nb(Si, Al)_2 does not exist in the Nb-Si-Al system at 1025 K.(2) MECHANISM OF DIP COATING USING Al-Si LIQUID :By dipping Mo in Si-saturated Al liquid, C40-type Mo(Si, Al)_2 layr formed on Mo. The C40-type intermetallic layr was comprised of needle-like Mo(Si, Al)_2 grains with Al-Si liquid at grain boundary. The needle-like grains grow by dissolution-precipitation process through Al-Si liquid at the interface between Mo(Si, Al)_2 and Mo.The mechanism of the growth of C40-type intermetallic layr is the dissolution-precipitation process through Al-Si liquid at the interface between Mo or Nb and the product layr. The difference of grain shape on Mo(Si, Al)_2 and Nb(Si, Al)_2 is discussed with the phase relation and supply and consumption of Al and Si from the liquid phase in the interface. The formation of the layr-by-layr structure in the Nb dipping was explained by the consumption of Al and Si with different ratios for D0_<22> and C40.(3) DEVELOPMENT OF CRACK=FREE COATING BY DIPPING USING Al-Si LIQUIDAddition of Cr, Nb, Ta and Ti in Al-Si liquid was carried out in order to prevent the formation of cracks of Mo(Si, Al)_2 layr on Mo surface with large curvature. The dipping of MO into Al-Si-Cr liquid leads to the formation of the crack-free layr. In the dipping with Al-Si-Cr liquid, (Cr, Mo) (Si, Al)_2 grains formed on the Mo(Si, Al)_2 layr. There is no change ofthe chemical composition and the growth rate of Mo(Si, Al)_2 by addition of Cr in Al-Si liquid.(4) LIQUID-PHASE REACTIVE SINTERING OF Mo-Si-Al POWDER MIXTURELiquid-phase reactive sintering of Mo-Si-Al powdr mixture were investigated. In the powder mixture with high Al content, self-propagation reaction occurred and Mo(Si, Al)_2 formed. The sintered bodies have porous structure. Less

(1)Al-Si液浸镀Nb将Nb在940K～1140K温度下浸入Si饱和的Al液中，在Nb界面上形成C40型Nb(Si_<0.9>，Al_<0.1>)_2层。金属间化合物层由直径为亚微米级的细小颗粒组成，颗粒间含有Al-Si液体。 Nb(Si, Al)_2层的生长速率由Nb/Nb(Si, Al)_2界面处的溶解-沉淀反应控制。 Mo浸渍中Nb(Si, Al)_2的生长速率比Mo(Si, Al)_2快3倍。在1025 K的非饱和Al-Si液体中浸渍Nb时,与Al-23 mol% Si液体形成C40型Nb(Si, Al)_2。生长速率比饱和Al-Si液体的情况更快。将Nb浸入Si含量约为20mol％的Al-Si液体中得到的产物层呈现出由C40型Nb(Si,Al)_2和D0_<22>型Nb(Al,Si)_3组成的层状结构。随着Al-Si液体中Si含量降低至5 mol%，产物层由D0_<22>型Nb(Al, Si)_3组成。他们的结果表明，在 1025 K 时，Nb-Si-Al 体系中不存在 C54 型 Nb(Si, Al)_2。 (2) Al-Si 液浸镀机理：将 Mo 浸入 Si 饱和的 Al 液中，在 Mo 上形成 C40 型 Mo(Si, Al)_2 层。C40 型金属间化合物层由针状结构组成。 Mo(Si, Al)_2 晶粒，晶界处有 Al-Si 液体。针状晶粒在Mo(Si,Al)_2与Mo界面处通过Al-Si液体的溶解-沉淀过程生长。C40型金属间化合物层的生长机理是Al-Si液体在Mo或Nb与产物层界面处的溶解-沉淀过程。从相关系以及界面液相中Al、Si的供给和消耗来讨论Mo(Si,Al)_2和Nb(Si,Al)_2晶粒形状的差异。 Nb浸渍中层状结构的形成是由于D0_<22>和C40不同比例的Al和Si的消耗所致。(3)Al-Si液体浸渍开发无裂纹涂层在Al-Si液体中添加Cr、Nb、Ta和Ti以防止Mo上Mo(Si, Al)_2层裂纹的形成。表面有大 曲率。将 MO 浸入 Al-Si-Cr 液体中导致形成无裂纹层。在用Al-Si-Cr液体浸渍时，在Mo(Si，Al)_2层上形成(Cr，Mo)(Si，Al)_2颗粒。在Al-Si液体中添加Cr,化学成分和Mo(Si,Al)_2的生长速率没有变化。(4)Mo-Si-Al粉体混合物的液相反应烧结研究了Mo-Si-Al粉体混合物的液相反应烧结。在高Al含量的粉末混合物中发生自蔓延反应并形成Mo(Si,Al)_2。烧结体具有多孔结构。较少的

项目成果

鎌田 弘之: "MoとAl-Si-X融体(X=Cr,Nb,Ta,Ti)との反応により生成するMo(Si,Al)2の組織とその制御" 1998年春期(第121回)大会日本金属学会講演概要. (1998)

Hiroyuki Kamata：“Mo和Al-Si-X熔体反应形成的Mo(Si,Al)2的结构和控制（X=Cr,Nb,Ta,Ti）”1998年春季（第121次会议））会议摘要日本金属研究所讲座（1998）。

南口 誠: "Si飽和Al融体中のNbおよびMo上に生成したダイシリサイドの微細組織" 1996年秋期(第121回)大会日本金属学会講演概要. 396- (1997)

Makoto Minamiguchi：“硅饱和铝熔体中 Nb 和 Mo 上形成的二硅化物的微观结构”日本金属学会 1996 年秋季（第 121 届）会议的演讲摘要 396-（1997 年）。

M.Nanko: "Microstructure of Disilicides Formed on Nb or Mo in Si saturated Al Liquid" Abst.1996 Fall Meeting of Japan Institute of Metals. 396 (1996)

M.Nanko：“硅饱和铝液中 Nb 或 Mo 上形成的二硅化物的微观结构”Abst.1996 年日本金属学会秋季会议。

高橋明男: "Si飽和Al融体を用いた超高温金属間化合物の合成" 1996年春期(第118回)大会日本金属学会講演概要. 90 (1996)

Akio Takahashi：“使用硅饱和铝熔体合成超高温金属间化合物”1996 年春季（第 118 届）日本金属学会会议摘要 90（1996）。

M. Nanko: "Formation of Intermetallic Compounds on Refractory Metals in Aluminum-Silicon Liquid" Abst.of the 3rd Okinaga Symp.Mater.Sci.Eng.Serving Soc.46- (1997)

M. Nanko：“在铝硅液体中难熔金属上形成金属间化合物” Abst.of the 3rd Okinaga Symp.Mater.Sci.Eng.Serving Soc.46- (1997)