| Co-Investigator(Kenkyū-buntansha) |
SASAGURI Nobuya KURUME NATIONAL COLLEGE OF TECHNOLOGY, MAT. SCI. AND MET. ENG.,PROFESSOR, 材料工学科, 教授 (50215737)
MORI Tetsuo PICHEMICAL AND APPLIED CHEMSTRY ENG. PROFESSOR, 生物応用化学科, 教授 (10037963)
IRIE Kazutaka DEPT. OF PHYSICS, PROFESSOR, 一般科目理科系(物理), 教授 (50149986)
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| Budget Amount *help |
¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1999: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
The purpose of this project is to research and develop the composite functional materials with high performance and their processing technique by cooperating with researchers of Keimyung University in Korea. The research was curried out on four themes and the following results were obtained :
(1) Alloy design, solidification process and wear resistant of high functional wear resistant cast alloys.
Three kind of alloys were designed to have totally 200/0 of strong cabide forming elements such as Cr, Mo, W and V so that two different types of each special coexist in each alloy. The carbon content was determinated referring to the parameter of carbon balance. Chemical composition and coexisting cabides of alloys are, Fe - 3%C- 10%Cr-5%Mo -5%W (M_7C_3+M_6C, alloy 1), Fe - 3%C - 10% V - 5% Mo - 5%w, (MC+M_2C, alloy 2) and Fe - 3.5%C - 17% Cr - 3%V (M_7C_3+(MC), alloy 3)
Solidification sequence of each alloy is as follows,
In all the specimens, the abrasion wear resistance was found to increase
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in the order of homogenized (AH), as-cast (AS), hardened and temped (AHFT) and as-hardened (AHF) states. In as-cast and homenized states, the highest wear resistance was obtained in alloy 2 and lowest one was alloy 3. In hardened and tempered states, the wear resistance of alloy 2 was greatly increased or greatest and it followed with difference by the order of alloy 3 and alloy 1. From these results, MC cabide having extreme hardness and matrix with martensite or tempered martensite and some retained austenite were found to be significant phases to improve the abrasion wear resistance.
(2) Surface improvement of materials using ion beam. MgO thin films have been widely used for protecting film of electrodes or phosphors in Plasma Display Panel (PDP), and the improvement of the efficiency of resistance has been required, because it is indispensable to achieve the long life of PDP. Fast Atom Beam Sputtering Method has been applied in order to estimate the resistance of these thin films against the fast atom bombardment with the energy of 2.0keV. The difference of energy and the momentum between the atoms and plasma particles in PDP must be considered in case of making exact estimation of resistance against plasma exposure ; rapid estimation is convenient if the relative estimation is required. The amount of the atoms that were bombarded upon the surface of the specimen was monitored by small electrode attached just in front of the upper specimen window and the current of the secondary electron were measured. After the irradiation by the same amount of atoms, the gap between sputtered area and un-sputtered area, which that was covered with small glass plate, were measured by Dektak3. MgO specimens were prepared by means of EB deposition method in Keimyong University ; of which thickness were 200 to 500 nm and these X-ray diffraction pattem were confirmed by thin film X-ray diffraction system. There were no differences between these specimens although the preparation conditions of them were slightly different in heat treatment after and in-situ deposition.
The results of estimation of the resistance against fast atom beam bombardment were summarized as follows ;
(1) MgO coated specimen shows better resistance than that of the uncoated glasses that were sputtered in the same way as to get the standard value.
(2) The resistance of the non-heat-treatment free MgO shows better performance than that of heat-treated specimens.
(3) The reason (2) has not been cleared from the results of X-ray diffraction pattern and the observation of the surfaces of the specimens by AFM, but to measer the hardness of these films have been expected to making it clear.
(3) Compounding of rubber, plastic and inorganic materials. The use of polyamide/aluminium pigment compounds instead of aluminium for automobile wheel cap will bring the reduction of cost and the environmental problems because of the elimination of coating process using toxic organic solvents. To prevent the increase of yellowness and decrease of the physical properties of nylon, Nylon6/inorganic pigments composites mixed with antioxidants or dispersion agents were prepared, and optimum amount of the antioxidants was investigated. Samples mixed with antioxidants showed less yellowness than a sample free of antioxidants. For the aging test in the 125'C oven, it was found that much slower decrease of the tensile strength occurred in the antioxidants added samples compared with those without antioxidants. Among antioxidants added, Irganox I 098 and B 1 1 7 1 were better antioxidants for Nylon6 systems. To get good dispersion of aluminium pigment in the Nylon6, it was found that the additives such as acrylic acid wax and Al coupling agent were effective. (4) Study of abrasion wear properties of composite multi-component white cast irons.
Composite multi-component white cast irons(Fe-5%Cr-5%Mo-5%W-5%V-2%C-Co) containing O, 2, 5 and I O mass % Co were prepared to clear the effects of cobalt content and heat treatment condition on hardness and properties of abrasion and sliding wears. The hardness of the cast irons decreased with an increase in cobalt content in as-cast and annealed states, but it increased conversely in the tempered state. It was found from the tests results using Suga type wear tester that the abrasion wear resistance lowered with an increase in hardness regardless of cobalt content. In the case of Pin on disk type wear test, the sliding wear resistance of the cast iron increased with increasing cobalt content and showed greatest in the sliding speed ranging from 3 to 4 m/s. It is considered that the sliding wear resistance could relate to the properties of oxide film produced during wear. Less
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