Sand erosion of silicon nitride by the impingement of alumina abrasives of an average diameterof 363 μm at a velocity of 65 m/s was investigated for a temperature range from room temperature to 919℃. Erosion rate increased with an increase of temperature, and also with an increase of impact angle except for room temperature. The erosion rate significantly increased above 800℃ where intergranular microfracture was observed on the eroded surface by SEM. X-ray diffraction study on the same silicon nitride specimen heated at 1000℃ level revealed the oxidation of the grain boundary phases, suggesting that the oxidation may accelerate the material removal by intergranular microcracking at high temperatures.

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New experimental technique(Disk-on-Rod Test) for the evaluation of thermal shock fracture behavior of ceramics was developed. The disk specimen with 20mm radius was heated to high temperature and quenched by means of contacting with the cool metal rod. The transient temperature on the disk specimen was measured by IR camera and thermal stress was calculated by finite element method. AE signals during thermal shock fracture were detected using an AE sensor attached on the bottom of the metal rod. The maincrack was initiated at the center of the disc specimen and was propagated with the deflection, arrested and re-propagated after several seconds. This behavior showed good agreement with the result of the thermal stress field and AE analysis.

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TiB_2 is expected to apply as machine element part and structures, because it has high melting point and high hardness. In this present study, (TiB_2-30vol%CeB_6) was added WC to progress its mechanical properties. After mixed TiB_2, CeB_6 and WC powder, hot-pressed at 2173K for 1.8ksec in vacuum with a pressure of 60MPa. And then effect of WC addition on microstructures and some mechanical properties of (TiB_230vol%CeB_6) composites were investigated. The result obtain are summarized follow :(1) The sinterability of (TiB_2-30vol%CeB_6)-WC hard materials is excellent showing approximatelytheoretical density. (2) Addition WC on (TiB_2-30vol%CeB_6) produced WB. These composites recognized existence of solid solution respectively. (3) (TiB_2-30vol%CeB_6)-WC hard materials made its mark on progress of some mechanical properties ; (TiB_2-30vol%CeB_6)-10vol%WC composite had micro-Vickers hardness were 25.2GPa and fracture toughness were 9.85MPam^<1/2>.

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A joint program to develop and evaluate a continuous fiber reinforced ceramic.matrix composite (CFCC) has been conducted by National Aerospace Laboratory, Ube Industries Ltd., Shikibo Ltd.. and Kawasaki Heavy Industries Ltd. The composite contains Tyranno^<TM> Lox-M grade fiber (Si 54%, Ti 2%, C 32%, O 12%, mass%) with an additional surface modification in order to improve interface properties. The composite exhibits excellent tensile strength at room temperature and creep strength at elevated temperature up to 1200℃, and is referred to as "NUSK-CMC" from the initials of the collaborators. To improve mechanical properties of NUSK-CMC above 1200℃ Tyranno^<TM> ZMI grade fiber (Si 56%, Zr 1%, C 34%, O 9%) was used in the new CFCCs. because Tyranno^<TM> ZMI fiber maintains high strength up to 1400℃. In this study, an orthogonal 3-D woven Tyranno^<TM> ZMI fiber / Si-C matrix composites were fabricated by polymer impregnation pyrolysis (PIP) process and chemical vapor infiltration (CVI) process. Three kinds of interpahses: pyro-carbon, CVD-h-BN, and coating free C-rich interphase were prepared for fiber/matrix interface. The composites with C and h-BN interphase and CVI-SiC matrix exhibited excellent tensile properties at room temperature.

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It is known that the CFCCs (continuous-fiber-reinforced ceramic matrix composites) are characterized by their non-linear fracture behavior, which is hardly found in monolithic ceramic materials. In order to develop materials for high temperature services, a sintered SiC (Tyranno-SA) fiber-reinforced oxide matrix composites were fabricated by using a slurry infiltration method and hot-pressing. As a result, MAS glass matrix composite with 50% Vf. of the fiber and a density of 2.84 g/cm^3 was obtained. As the mechanical properties at room temperature, the three-point flexural strength and quasi-static adsorbed energy.were 500 MPa and 6,000 J/m^2, respectively. Without graphite or an h-BN precoating on the surface of the fiber, pull-out and bridging of the fibers from the matrix was found, and this leads to a high value of the adsorbed energy. By TEM observation, nano-scale crystalline products were found between the fibers and the glass matrix. The push-out test reveals that this layer causes the appropriate debonding of the interface during the fracture process of the composite. Furthermore, eutectic composition of a sintered Al_2O_3-YAG matrix composite was fabricated. In order to control the interfacial strength between SiC fiber and the matrix, 1 μm thickness of a CVD-graphite (Pyrograph, TOYO TANSO Co. Ltd.)_was coated on the fiber. The-flexural strength and the adsorbed energy were 580 MPa (at R.T.), 760 MPa (at 1573K) and 11,200 J/m^2 respectively. In spite of these excellent mechanical properties, transverse crack in the matrix was inevitable which was caused by thermal residual stress after hot-pressing. This crack has a possibility to deteriorate the anti-oxidization ability of the material.

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Research Institute of Advanced Materials Gas-Generator (AMG), which is a joint effort by the Japan Key Technology Center and 14 companies in-Japan, has, since 1993, been conducting technological studies on an innovative gas generator that will use 20% less fuel, weigh 50% less, and emit 70% less NOx than the conventional gas generator through the use of advanced materials[1]. In the course of R&D, the feasibility of applying the gradient composite material with ceramic matrix composite (CMC) and glass matrix composite (GMC) which is expected to reduce the thermal stress of actual parts with temperature distribution was evaluated based on its mechanical and thermal properties, productivity and stress analysis for an actual part as a combustor liner with 500 mm in diameter, and non-cooled combustion tests in the condition of 1873 K as the liner outlet temperature. Through our studies we have confirmed the applicability of the selected CMC/GMC hybrid composite as a combustor liner.

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Intermetallics-matrix-composite foams were synthesized by a combustion reaction. The elemental powders of nickel and aluminum were blended by a molar ratio of Al/Ni=3. The compacted powder blend was heated to ignite the reaction, which resulted in the Al_3Ni formation. The enthalpy control during the combustion reaction was carried out by adding a reaction enhancer ( [Ti+B_4C] blended powder ) to increase the heat of reaction. Blending a sufficient amount of the reaction enhancer successfully made the Al_3Ni composite foam with more than 80vol% porosity. The effects of preheating, density of the green compact, addition of reaction enhancer were also investigated and will be discussed in the presentation.

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Al_<18>B_4O_<33> whisker and SiC particle and Al_<18>B_4O_<33> particle/whisker reinforced magnesium alloy matrix composites were fabricated by compo casting. The reinforcements distributed uniformly in all composites. By hot-extrusion or squeeze casting in semi-solid condition after compo casting, the pores with several decade and hundred micro-meter in diameter in as-cast composites disappeared, the uniform distribution was remained and the grain size became to be small. In Al_<18>B_4O_<33> whisker /AZ91D composite, the uniform reaction layer 'MgAl2O4' with 10-20nm in thickness formed in compo casting. This layer prevents the direct reaction between the whisker and the matrix in high temperature.

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Mechanical properties and microstructure have been investigated on a 17 vol% SiC paniculate-reinforced ZK60 magnesium-based composite (ASTM designation: ZK60/SiC/17p). The composite exhibits a high specific strength as well as a maraging steel, and limited ductility < 1%. In order to enhance the ductility under dynamic loading, additional extrusion was performed to homogenize the morphology in distributed reinforcements. It has been revealed that a homogeneous distribution of reinforcements is effective to enhance the ductility under dynamic loading.

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Elastic moduli and damping capacities of 70vol%SiC/Al, 55vol%SiC/Al, 60vol%Al_2O_3 /Al, 70vol%AlN/Al and 30vol%SiC/Al composites were studied by using torsional vibrasion technique. The temperature-dependent damping was mesured at temperatured from 293K to 85OK. A damping relexation peak was observed at 〜600K on each samples. The damping peak at 〜600K is caused by interfacial diffusion between ceramic particles and Al interface. The activation energy of each iterfacial diffution was 40.7〜56.7KJ/mol on SiC/Al, 62.1KJ/mol on Al_2O_3 /Al and 27.7KJ/mol on A1N/A1. The increase of the damping capacity in all samples over 700K is caused by the plastic flow at the grain boundary. The activation energy of plastic flow was 42.3〜119KJ/mol.

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Titanium-based metal-matrix composites (MMCs), reinforced with 20vol.% TiB particle is produced by mechanical alloying-spark plasma sintering. The compacting of the sinteredshows 98.8% in relative density and about 630Hv. In order to improve the density, hot rolling (reduction ratio of 2.5:1) is conducted. The results show that the vickers hardness increases by about 5%. and 99.9% becomes in relative density. The tensile test is conducted under the quasi-static loading, the ultimate tensile strength of 1173MPa exhibiting. However, it breaks during the elastic deformation. Also, as loading rate increases from 10^1 to 10^3s^<-1>. the dimple becomes large, and deep.

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In development of continuous fiber reinforced titanium alloy matrix composites (TMCs), the enormous production cost resulting from preliminary forming and elaborate tooling for consolidation is the fatal difficulty for practical application. In order to reduce the production cost, superplastic-formable TMC sheets (SCS-6/Ti-4.5Al-3V-2Fe-2Mo) were developed, and deformation characteristics and cavitation behavior were investigated. In this study a new low-cost-manufacturing process for titanium matrix composite blade has been developed. This process consists of three steps : (i) consolidation of flat TMC panels of 20mm thickness, (ii) superplastic forming to twist the TMC panel and (iii) machining of the twisted TMC to a final blade configuration. Using this process, production cost of a TMC blade can be reduced to 1/5 of the cost for the TMC blade fabricated by the conventional manufacturing process.

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Al-Al_3Ti FGMs were fabricated by a centrifugal method with three different G numbers, i.e., G=10, 30 and 50. Three types of wear specimens were prepared taking into account the Al_3Ti platelet morphology in. the thick-walled FGM ring; the Al_3Ti platelets were arranged with their platelet planes nearly normal to the radial direction as a result of the applied centrifugal force. A significant anisotropic wear resistance was noted at the ring's outer region whereas anisotrppic wear resistance was not observed at the ring's inner region. Based on experimental results, the origin of anisotropic wear resistance in Al-Al_3Ti FGMs was discussed.

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In our previous studies, it was found that Al-Al_3Ti FGM fabricated by a centrifugal method contains anisotropically oriented Al_3Ti platelets. The orientation of Al_3Ti platelets is found to be gradually distributed in the FGM as well as the mean volume fraction of platelets. Since the anisotropy of orientation of the reinforcement is likely to affect greatly the mechanical and physical properties of the composites, detailed knowledge of orientation distribution of the particles in FGMs is a for requirement predicting the mechanical properties of the FGMs. In this study, a corundum/aluminum-platelet is used as a model system to investigate the orientation effects in the platelet-reinforced' FGM fabricated by the centrifugal. Every aluminum-platelets are bared from the corundum matrix, and three-dimensional orientation for the platelets is directly observed. Based on experimental results, the origin of the orientation of platelets in the FGMs fabricated by the centrifugal methods will be discussed.

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Extruded aluminum shapes have been used for constructive components of the automotives in order to reduce the total weight of ones in the last several years. This paper describes a new manufacturing method of the bumper inner with curvature, knowledge of conform extrusion for the condenser tubes and a new extrusion procedure with shear strain. In experiment of shear extrusion, tensile strength and elongation of products are better than those of the ingot made material. On the conform extrusion, the result of numerical simulation based on upper bound theorem shows the extrusion condition of minimum total energy. And bending of bumper inner is calculated by FEM. It is clear-that bending process is influenced by the geometry of cross section.

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The authors tried to work extruded square tube containing a cross rib in the draw bending process. For practical use, high rigidity and three-dimensional bending products, this tube was applied to this process: This report describes as follows; (1) optimization of thickness of a cross rib analyzed by FEM, (2) investigation of buckling and splitting limit of the bending by the experimental results, (3) the effect of tube-comers such as radius (r.) and chamfer in this process. As a result of these investigations, we could develop the frame of a rehabilitated tricycle.

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Aluminum alloy die-casting is a method of injecting molten metal into die cavity at high speed and high pressure, and it has high productivity and makes castings having good surface property and measurement precision. But it was difficult to make castings having high quality, because it was easy to roll up air in casting process. In late years, high vacuum die-casting technology was developed and applications to parts needed high strength and toughness became possible. Parts casted with these methods have been applied as parts of body and chassis of automobile which had not been able to apply.

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It is well known that cold worked thermoplastics have a tendency to change their shapes at elevated temperatures. The phenomenon is called the strain recovery or the shape memory effect. This paper describes forming processes for bolts and rivets by utilizing strain recovery of polycarbonate bars.

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A new process for tube ironing, the "Planetary Conical Rolling" (PCR) process, is proposed. A number of rollers rotate around the cone while revolving around their respective axis, preventing sliding friction which is the main cause of galling and breakage in the conventional ironing process. Additionally, a large deformation and a high pressure can be applied locally to the material under each roller because this process is an incremental process and the axis support cone is highly rigid. Taking advantage of these features to produce a hybrid tube, lap pressure welding by PCR process between aluminum alloy (A5052) and pure copper (Cl100) was discussed in this paper. From the measurements of bonding strength, it was found that the relative strength of outer tube against inner tube mainly affected the bonding strength. That is, high bonding strength was obtained when the relative hard tube was set on the inner side. This is explained by the difference of plastic zone in both tubes depending on the material combinations.

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We developed a process integrated machine for sheet metal fabrication, proposing a new bending method. Through the application of this new bending method to sheet metal fabrication, it became clear that this method can apply to joining as well.

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We succeeded in mass production of epoch-making single-layer metal gasket by laser welding. The effects of manufacturing conditions on the joint strength are investigated experimentally. Based on the experimental results, (1)Joint strength increases linearly with the increase of welding bead width. (2)If there is a gap between shim and substrate which are welded together, joint strength becomes small. Therefore, clamping at welding is an Important manufacturing conditions. (3)The range of focusing the position of laser beam to get the-optimum joint strength is quite narrow.

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In recent years, large item small volume production, shortened trial production period, and countermeasures against environmental issues, etc. have been increasingly demanded in every manufacturing industry. Laser processing utilizing the energy of laser beam is one of the few processing methods that can improve production processes to meet these demands. This paper introduces processing capabilities,processing qualities, and application examples of the latest laser processing machines.

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Shave-joining process essentially consists of press shaving a bore wall within a main material by sharp edges of the harder projection on a dissimilar material to engage two or more elements. The method can be successfully applied for the lap joint of metal sheets. Sharp edges of steel screw threads (rivet) can easily shave the bore within lapped materials into the female screw to join between sheets of aluminum or mild steel. The process has many merits such as simple method, lower working load, reduced noise, one blow operation, no need of caulking and heading, cold or warm working, and freedom of material combination. Furthermore, the lap joint has excellent properties such as high and stable joining strength, air tightness, flat surface, and possibility of disassembly.

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Instead of costly conventional bonding methods a new manufacturing process was developed for high-performance rotary joint, which was an important element in machine system to pass through oil and other liquors. The mechanical seal of ceramics such as Al_2O_3,TiB_2,SiC and Zr_2O_3 was shave-joined with austenitic stainless steel housings for stator or rotor, comparing with a seal of cemented carbide alloy. The joining temperature of steel is at 100-600℃ and shaving depth is selected from the value of 0.15-0.5mm. The developed rotary joint was confirmed to possess sufficient properties required for the practical use: high joining strength and the stability.

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To meet recent diversified requirements for camshaft as an automotive valve train component, authors designed a composite camshaft which includes consideration to environment protection and established technique for mass production of highly value added composite camshaft manufactured by shave joining process together with development of its assembly machine through wide range discussion on possibility of its practical use via basic experiments and prototype production.

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In cutting operation by a knife-edged cutter, horizontal motion paralleled to edge greatly decreases cutting force. This paper shows that friction at the tip of cutter by horizontal motion causes separation force in cutting plane, and verifies theoretically and experimentally. This deduction is verified by cutting test with Flat-blade cutter (Cutting edge is flatness.) and analysis of separating process .using FEM simulation method. The results obtained are as follows: (1) By cutting test using a special blade with Flat-blade cutter under several frictional conditions, it is supposed that horizontal friction causes large tensile stress at the vicinity of edge in cutting material vertical to the cutting cross section. (2) FEM calculation also shows that friction caused by horizontal motion makes cutting material be easily separated.

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As a result of the trend of consumer demand for many metallic shell products, the study of the rapid and flexible sheet metal forming has received considerable attention. In the present paper, a rapid and flexible draw-bend forming machine using a slitting die has been developed for the small-batch manufacture of shin strips with a curvilinear cross section. Because one-stage forming with a slitting die could not prevent the growth of the wrinkle and the warp of formed strip shell of shin metallic sheet, two-stage forming method was invented using two slitting dies and high quality strip goods with a curvilinear cross section were formed by controlling the position of the dies.

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Combined effects of forming condition on deep-drawability of square cups were studied. In order to investigate the fundamental deep-drawability , drawing of rectangular shell of steel sheet was carried out under various deep-drawing condition . (1) As for the square cups, the increase of sheet thickness cause the increase of deformability and elongation, and the control of reduction of sheet thickness. (2) As for the die-radius of drawing, the increase of die-radius cause the increase of elongation and the control of reduction of sheet thickness. (3) The shape of square cups was close connected with sheet thickness, die-radius, and clearance. For example, good deep-drawing of SPCEN sheet could be finished, under the condition of optimum blank shape, blank holding force 5(kN), punch speed 0.5(mm/sec), die-radius 6.0(mm), the sheet thickness 0.7, 0.907 [mm], and die-radius 8(mm), the sheet thickness 1.2 [mm] .

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Groove forming for O-ring use was investigated experimentally using a CNC profile rolling machine. The geometry of the groove investigated was 5mm in width and 4mm in depth. The diameter of the shaft (S45C) was 40mm. Optimal groove forming conditions found were as follows: die shape: semi-circular; forming time: 18.3 seconds; number of revolutions of die: 12rpm. When the number of revolution of die was less than 14.5, flaking at the side walls was successfully suppressed.

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Shape controlled extrusion apparatus was developed to fabricate an aluminum square pipe with changing it's inner and outer size during extrusion. The inner size of the pipe was changed by shifting a tapered mandrel, and the outer size was also changed by shifting four segment dies It was found that the plasticine square pipes with the extrusion ratio of 2-6 are produced using this apparatus. Finally, extrusion of A1050 aluminum alloy was performed.

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The bars before drawing are produced by hot rolling and heat treatment process. But, by these process the scales are generated on surface of bars. Before drawing the process that the scales are removing is necessary. The pickling or the shot blasting is usually used in this descaling process. In the residual stress after bar .drawing by pickling and shot blasting was measured by X-ray and slitting method. As results, if the bars are demanded high fatigue quality on surface, the pickling is more effective than the shot blasting.

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The axial tensile residual stress is generated on surface of bar after drawing. This residual stress causes bending and decrease of fatigue strength by machining or by heat treatment process. Therefore reduction of residual stress is very important for industrial use. In this study, Angle-type die and Circle-type die were used to research the optimum geometry of die. The effect of bearing length on residual stress was also studied. As results, the optimum geometry of die is : (1)entrance of die had better-to use angle-type, (2)corner radius is enlarged comparatively in the exit and (3)bearing length is enlarged.

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The grain refinement is noticed to way to enhance strength.of metal materials. Recent studies have shown that this microstructure with fine grain size can be achieved by imposing extremely large plastic strains during work processing. Mg alloy has characteristic properties like hydrogenation treatment in hydrogen and dehydrogenating in vacuum at high temperature. Hydride precipitation MgH_2 was obtained in this hydrogenation treatment, was more useful to produce on high-density dislocation in alloy like introducing dislocation pileup source. This paper presents possibility to be occurred grain refinement of 5083Al(Al-Mg alloy) utilizing this phenomenon. Hydrogenated material was carried out by heavy cold rolling to be induced high stored strain energy. Then, to obtain the fine grain sized material, heat treatment was performed to do rapid recrystallization in salt bath. It was shown that the grain size of dehydrogenated 5083Al(Al-Mg alloy) is more fine in comparison with that of non-hydrogenated.specimen. After rolling, Vickers hardness of hydrogenated specimen was higher than that of non-hydrogenated specimen.

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The inner surface roughness of tubes was improved by giving high contact pressure and large plastic strain. A new protrusive die on bearing portion is applied for the ultra-smooth outer surface of drawn bar and wire. This new die gives high pressure with large plastis strain ,and improves surface roughness in comparison with the normal die.

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In this research, wear and friction properties of a magnesium alloy have been studied in pin-on-disk under dry condition at room temperature. Used specimens are ZK60 magnesium alloys that have different grain sizes, and they are examined to investigate the influence of grain size exerted on friction and wear properties. As a result, it was proved that wear-resistance improved with increasing grain size. The coefficient of friction was about 0.3 for the coarse-grained alloy, and decreased with refining the grain structure.

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Ring on block sliding experiments were carried out in nitrogen atmosphere in order to evaluate wear behaviors and film lives of coated tool steels prepared by CVD, aiming at improving performances of tools for aluminum plasticity processes such as extrusion dies. Coated blocks of tool steels, SKD61 and SKH51, with three layers of TiC/TiCN/TiN or single TiC layer were examined sliding against rings of aluminum alloy, A6063-T5, under a dry condition comparing with gas-nitrided ones. A characteristic growing process of failures for coated specimens was observed: after slid to a certain distance, a small damage on the film surface took place under a transfer layer of aluminum alloy, and with a little increase of sliding distance, the damage expanded rapidly toward downward. It seems to resemble the generation of the failures, which was observed in TiC/TiCN/TiN coated extrusion dies. The film lives of coated specimens were longer than the life of gas-nitrided one and a TiC coated specimen of SKH51 had a marked longest film life.

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Owing to the hardness and mechanical stability of thin hard coatings, they have a wide range of applications. For example, TiN coating has been used as a wear resistant coating. Tribological properties of PVD coatings produced by an arc ion plating process have been studied. The principal advantage of this method is to deposit coatings at lower temperature. The purpose of this study is to collect the basic data of friction and wear resistant properties. TiN coatings with a film thickness of 3μm are deposited on the substrate (SKD11) by PVD arc ion plating process. For sliding conditions changing the sliding speed and the load, the friction coefficient and the wear rate are measured using by ball-on-disc tester. It is found that they depend on the sliding conditions.

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The structure made of aluminum alloy, which was stiffness-reinforced with CFRP bonded adhesively to decrease vibration, was put to practical use. To put CFRP adhesive structure to practical use, it was necessary to obtain the fatigue life. In current standard test methods, there wasn't an suitable test method for the design of this application. Therefor, we had to use the full scale model equivalent to actual structure each time. In this study, we suggested a compact model for the fatigue life estimation of reinforced structure combined with CFRP bonded adhesively. And fatigue tests using full scale models and compact models were carried out. As the result, we obtained the good interrelation between the fatigue life of the full scale model and the life of the compact model.

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Fracture toughness of a hybrid material, which consisted of aluminum alloy and CFRP bonded adhesively, was investigated experimentally. Since fracture probably occurred along the interfaces between an adhesive and the adherends, mixed mode conditions took place near the crack tips due to the presence of different materials. In order to clarify the.influence of the mode ratios on the fracture .toughness, mixed mode bending tests of hybrid-material specimens were carried out changing the ratio of mode I and II. The fracture toughness decreased as portion of mode II increased. Cracks in the specimens propagated always along the interfaces between the adhesive and CFRP.

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Young's modules and Poisson's ratio of adhesive layer are important constants for stress analysis of adhesive joints. These constants are usually determined from testing of adhesive bulk material. There are controversy as to whether these constants are equal to those of adhesive, for reason that thickness of adhesive layer is very thin and stress field of adhesive layer is complicated for bonding interface. In this paper, a highly sensitive displacement measuring system using optical fiber sensor is demonstrated to exactly evaluate Yong's modules of adhesive layer in adhesive butt joints under tensile load. The apparent Yong's modules is compared with those of strain gage method and adhesive bulk material.

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A polymeric material has been studied to predict the solid polymer deformation. Constitutive equations reflecting rotation and direction of polymer chain has been formulated using the theory of polymer network models. The eight chain model accurately captures character of polymer deformation which requires only two parameters. The chain extension in this network model reduces to a function of the root-mean-square of the principal applied stretches as a result of effectively sampling eight orientations of "principal stretch element. The purpose of this paper is to evaluate the change of mechanical properties in terms of Epoxy/Phenoxy blend ratio and to apply the theory of polymer network model to this polymer alloy. The Visco-elastic test under various temperature shows that macorscopic structure of resin was formed Phenoxy over 60% of blend ratio.

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Rubber modified epoxy adhesive has been widely used to structure fields due to high toughness. The important fracture mechanism of the rubber modified epoxy adhesive is the void formation by rubber particles and the following damage zone propagatioa Hence, recently damage mechanism of the adhesive has been investigated. However, most studies were conducted under static load conditions, there are few studies about fatigue degradation behavior of the rubber modified epoxy adhesive. In this study, the damage behavior of the adhesively bonded butt joint under cyclic loading conditions has been investigated using a rubber modified adhesive. The strain of the adhesive layer were monitored by using strain gages pasted on the adhesive layer. Damage of the adhesive layer was discussed based on the stress-strain loop under cyclic loading.

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The adhesive strength of butt joints subjected to impact tensile loads under high temperature was studied. The specimens are cylindrical butt joints. The electric furnace heats the adhesive joints. Three kinds of organic adhesives and one kind of inorganic adhesive were used. The impact adhesive strength of the organic adhesives decreased with the increasing of temperature. And the strength was approximately σ=0MPa at about T=200 ℃ even if it were heat-resisting organic adhesives. The strength of the heat-resisting inorganic adhesive measured at the T=200 ℃ , however, is equal to the strength measured at the room temperature approximately. Also the impact adhesive strength of the organic adhesive used in this paper was. much higher then the static adhesive strength.

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The stress distribution in the adhesive layer of the cruciform adhesive joint under the biaxial load was calculated by the finite element method (FEM) analysis. As a result, the shearing stress estimates to the von Mises criteria. Biaxial loading tests of cruciform adhesive joint with rectangular bonded shape were confirmed experimentally. The shearing strength was in independence to the load ratio. From above-mentioned result, in the case of resin which can use von Mises yield criterion, it was estimated that the fracture stress of cruciform adhesive joint be used as the strength of adhesive.

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The volume shrinkage ratio and the residual stress that occurs at the curing shrinkage of acrylic resin were measured. The volume shrinkage ratio was measured with the laser displacement detector system and the dilatometer. The volume shrinkage ratio of acrylic resin was about 16%. Most of the volume shrinkage resulted in about 12 minutes after the mixture. The residual stress in interface of adhesive layer was calculated by measuring the residual strain of adherend. The influence of the residual stress on the adhesive strength must be considered.

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The purpose of this study is to investigate the fracture toughness and fracture behavior of the acrylic adhesive using DCB joints under Mode I loading. The DCB joints were fabricated by using the acrylic adhesive and adherends of steel, and the loading-unloading tests of these joints under Mode I loading were performed by an Instron testing machine according to the ASTM D3433-75 standard. The elastic-plastic fracture toughness J_<Ic> of the acrylic adhesive was also attempted to evaluate according to the JSME S001-1992 standard. The fracture toughness G_<Ic> showed a tendency to increase with increasing crack length, and the thicker the adhesive layer, the higher the fracture toughness G_<Ic>. On the other hand, the elastic-plastic fracture toughness J_<Ic> increased linearly with increasing crack extension, and the thicker the adhesive layer,the higher the crack extension resistance given by the slope of R-curve.

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