- Studies on Microstructural Phenomena Caused by Atomic Diffusion in Sintered Materials
-
Koji Hayashi
-
J Korean Powder Metall Inst. 2003;10(6):374-382.
-
DOI: https://doi.org/10.4150/KPMI.2003.10.6.374
-
-
 Abstract
 PDF
- During the sintering of powder materials, many these are microstructural phenomena are caused by atomic diffusion. (1) neck formation and compact densification, (2) grain growth, i.e., growth of matrix grains and dispersed grains, (3) alloying or generation of compound, (4) generations of peculiar and hard layers near sintered compact surface, etc. The studies of the present author and co-workers on these phenomena which were carried out during 40 years are briefly introduced.
- Recent Development of Science and Technology of Hard Materials in Japan
-
Koji Hayashi
-
J Korean Powder Metall Inst. 1998;5(4):303-311.
-
-
-
Abstract
PDF
- Hard materials such as hardmetal, coated hardmetal, cermet, ceramics and diamond or c-BN sintered compact are a kind of grain-dispersed alloy with high volume of hard particles. These are used for cutting tools, wear-resistant tools, rock bits, high pressure apparatus, etc. The annual production in Japan is about 1.7 billion dollars (200 billion yen). This is greatly owed to the development in science and technology which has been accomplished by applying new concepts such as fine or uniform grain microstructure, orientation of crystal grains, functionally graded material, artificial lattice and coherent bonding in recent years. In this review, the development in recent years in Japan is briefly summarized.
- Microstructure and Flexural Strength of Hardmetals
-
Koji Hayashi
-
J Korean Powder Metall Inst. 1994;1(2):119-198.
-
-
-
Abstract
PDF
- The characteristics of various important microstructural factors of WC-base hard- metals (cemented carbides) such as the amount of Co metal binder phase, the carbide grain size, the microstructural defects acting as a fracture source, the solid solubility of tungsten in the binder phase affected by the carbon content, the precipitation of Co_3W, the domain size of binder phase, the formation of beta-free layer or Co-rich layer and CVD or PVD coated layer, and the effects of these factors on the flexural strength of the hardmetals are reviewed.
|
kpmi
