A Consideration on TiC-Core/(Ti,Mo)C-Rim Structure of TiC-Mo2C-Ni Cermet in Relation to Hypothesis "Exhaustion of Diffusion-Contributable Atomic Vacancies in Core/Rim Structure" (特集 硬質材料)
スポンサーリンク
概要
- 論文の詳細を見る
TiC-core/(Ti, Mo)C-rim structure in TiC-Mo<SUB>2</SUB>C-Ni cermet where the equilibrium phase of carbide is only (Ti, Mo)C is known to be not generated by solid-diffusion process, but by solution-reprecipitation process in the case of usual sintering temperatures (1528-1723 K). On the other hand, in our recent study on the microstructure of Fe-66.7at%Si peritectoid alloy where the equilibrium phase is FeSi<SUB>2</SUB>, it was found that FeSi-core in FeSi-core/FeSi<SUB>2</SUB>-rim structure hardly disappeared by solid-diffusion process in the compact inside, but relatively easily disappeared and/or shrunk near the compact surface to the depth of FeSi-core size (about 15μm) by heating at high temperature. The phenomenon in the compact inside could be explained by our newly proposed hypothesis "Exhaustion of diffusion-contributable atomic vacancies in core/rim structure".<BR>In this study, it was investigated in relation to the above hypothesis whether TiC-core in the compact inside disappears or not due to solid-diffusion process by heating at 2073-2473 K which are extremely higher than the usual sintering temperature. As the result, it was judged that TiC-core in the compact inside really disappeared by solid-diffusion process at 2273-2473 K, differing from FeSi-core in the compact inside. Based on these results on Fe-66.7 at%Si alloy and the cermet, it was generally concluded that our new hypothesis can be applied to the alloy where the rim phase is a stoichiometric compound unable to dissolve the core elements and also the diffusion from the core to the rim is not thermodynamically allowed like in Fe-66.7 at% Si alloy, but not to the alloy where the rim is a solid solution able to dissolve the core elements and thus the diffusion from the core to the rim is thermodynamically allowed like in the cermet.
- 社団法人 粉体粉末冶金協会の論文
- 2004-05-15
著者
-
HAYASHI Koji
Institute of Industrial Science, The University of Tokyo
-
Yanaba Yutaka
Institute Of Industrial Science
-
TAKAHASHI Toshiyuki
Tungaloy Corp.
関連論文
- Synthesis of New Mono-Carbonitride(W, Mo)(C, N) Powder by Heating W-Mo Alloy+C Mixed Powder in High-Pressure Nitrogen Gas (特集 硬質材料)
- Synthesis of New Mono-Carbonitride Mo(C,N) Powder by Heating Mo+C Mixed Powder in High-Pressure Nitrogen Gas (特集 硬質材料)
- Synthesis New Cabonitride W(C, N)Powder by Heating W+C Mixed Powder in High Pressure Nitrogen Gas
- Applicabilities of Equations of σ_m=ψK_S_^ and σ_d^=σ_O^+Ka^ to Soda Lime Glass
- Effects of Test Piece Length,Composition and Measuring Atmosphere on PTCR Characteristic of Porous BaTiO_3-Based Vacuum-Sintered Compacts Added with Partially Oxidized Ti Powder
- Applicabilities of σm=ψKICSmf1/2 and σd-1=σ0-1+Ka1/2 to KIC Estimation of Hardmetals, Cermets and Ceramics (特集 硬質材料)
- Effect of Sintering Cooling Rate on V Segregation Amount at WC/Co Interface in VC-doped WC-Co Fine-Grained Hardmetal
- A Consideration on Grain Growth in WC-Co Fine Grained Hardmetal by Numerical Calculation Based on Alloy Model with Three Kinds of Grain Sizes (特集 硬質材料)
- Development of Two New Methods for Estimating Fracture Stress of Fractured Hard or Brittle Materials from Its Fragments (特集 硬質材料)
- A Consideration on TiC-Core/(Ti,Mo)C-Rim Structure of TiC-Mo2C-Ni Cermet in Relation to Hypothesis "Exhaustion of Diffusion-Contributable Atomic Vacancies in Core/Rim Structure" (特集 硬質材料)
- Application of New Estimating Method of Fracture Toughness by Use of Equation of σ_m=ψK_S_^ to High Speed Steel
- Application of an Equation Representing Reciprocal Fracture Strength versus Square Root of Fracture Origin Size to the Estimation of Fracture Toughness of Hard or Brittle Materials (特集 硬質材料)
- Applicability of New K_ Estimation Method Using Equation σ_m=ψK_S_^ for Hard or Brittle Materials to Ductile Hot Tool Alloy Steels
- Automation of Measuring Fracture Surface Area and Shortening of Measuring Time for Hard Materials (特集 硬質材料)
- Measurement of Kinetic Energy of Flying Fragments in Bending Test of WC-10mass%Co Cemented Carbide (特集 硬質材料)
- Proposal of Atomic Models for Formation Process of Carbonitride W(C,N) Synthesized by Normal-and High-pressure Methods
- One Evidence for New Hypothesis "Exhaustion of Diffusion-Contributable Vacancy in Core/Rim Structure
- Open Pore Generation on Sintered Surface of Ti (C,N) Base Cermet and Its Mechanism (特集 硬質材料)
- Effects of Starting Powder Size and Ball-Milling Time on Microstructure of WC-Co Base Cemented Carbides Prepared from W+C+Co Base Mixed Powder (特集 硬質材料)
- High Temperature Strength of WC-Co Base Cemented Carbide Having Highly Oriented Plate-Like Triangular Prismatic WC Grains (特集 硬質材料)
- Mechanisms for Formation of Highly Oriented Plate-Like Triangular Prismatic WC Grains in WC-Co Base Cemented Carbides Prepared from W and C Instead of WC
- Effects of N/(C+N) Atomic Ratio and Amount of Ti(C,N) on Chemical Reaction of Al2O3-Ti(C,N) Ceramics with Ni Plate (特集 硬質材料)
- Microstructure and Mechanical Properties of New WC-Co Base Cemented Carbide Having Highly Oriented Plate-Like Triangular Prismatic WC Grains (特集 硬質材料)
- Microstructual Change During FeSi_2 (β-phase) Formation and the Cause for Acceleration of the Formation Rate by Addition of Pd in Mn-doped Fe-66.7at%Si Alloy
- Synthesis of New Mo(C,N) Powder by Heating Mo Powder in CH4+NH3 Mixed Gas of Normal-Pressure (特集 硬質材料)
- Products Obtained by Heating Cr Powder in CH4+NH3 Mixed Gas of Normal-Pressure (特集 硬質材料)
- Effect of Preheating Profiles on Nitrogen Contents of Mono-carbonitrides Synthesized by Heating W, Mo and W-Mo Powders in CH4+NH3 Mixed Gas of Normal-Pressure (特集 硬質材料)
- Synthesis of New(W,Mo)(C,N) Powder by Heating W-Mo Alloy Powder in CH_4+NH_3 Mixed Gas of Normal-Pressure
- Preparation of Fe_4N Sintered Compact by Heating Green and Sintered Compacts of Fe Powder in Flowing NH_3+H_2 Mixed Gas