Bonding material is one of the most important factors affecting the performance of a grinding wheel. Although some general guidance of bonding material selecting is available for surface grinding, there are no published data for ceramic ball grinding which is a much different grinding process from surface grinding. SD8000 diamond wheels of three different bonding materials, vitrified, resinoid and metal (bronze) were used in grinding experiment of Si_3N_4 ceramic balls under a constant grinding load of 50 N (2 N/ball) and a wheel speed of 810 rpm. It is found that metal bonded wheel shows the best grinding performance among the three wheels.

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It is desirable from industry that the polishing process using loose abrasive is replaced by grinding process. This paper explores this possibility by investigating the effect of the free radical reaction oh the grinding performance of SD8000 metal bonded diamond wheels. The free radical was generated with aid of TiO_2, a kind of photo-catalyst. Experiments were conducted for ceramic ball grinding with a metal bonded diamond wheel of SD8000. It is found that the material removal rate increases by a factor of about 6 when adding 7.5wt% of TiO_2 into grinding fluid which was water in this experiment.

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There are great anticipation of high quality machined components using difficult-to-cut metals such as stainless steel having excellent mechanical and chemical properties. The high accuracy cutting technic of stainless steel has been increasingly required in a wide field of industries. The diamond bite which is generally used to produce, by cutting, ultra-precision components are not sufficiently successful to face-turn the stainless steel. The tool life of the diamond bite is too short to produce the ultra-precision components. In this research, three kind of commercial cutting bite is used for ultra-precision cutting of stanless steel SUS 316. We found that the special coated cemented carbide is found available for ultra-precision cutting of stainless steel SUS316, because the bite wear is so small and the finished surface roughness is smoother than about 100nm(P-V). The surface roughness of face turned stainless steel is influenced considerably by the tool wear and accretion of workpice matel as stainless steel.

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This paper presents new experimental data of the inelastic behavior of type 316 stainless steel under uniaxially/ multiaxially cyclic loading at elevated temperatures ranging from the room temperature to 650℃. The uniaxial stress-state experiments of tension, creep and ratcheting of isothermal and temperature variation (in-phase/out-of-phase) conditions were Performed. Besides, some multiaxial ratcheting tesis were conducted at several temperatures. In order to describe the inelastic behavior at elevated temperatures, a constitutive model of cyclic viscoplasticity has been presented in the present work. The stress-strain responses calculated by this model agree well with the corresponding experimental results.

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The effect of the level of plastic deformation on the ductile-brittle transition temperature (DBTT: T_c) of sintered molybdenum was examined by the tensile testing. Specimens with four levels of 0, 10, 25 and 50% in thickness reduction (R) were prepared by a rolling at 873 K and tensile tests for smooth and notched specimens were carried out at any desired temperatures between 163 K and 473 K and at a strain rate of 5.5×10^<-3> s^<-1>. The results obtained in this work are summarized as follows: In both the smooth and notched specimens, the transition temperatures were monotonously lowered with increasing the thickness reduction. The presence of an edge notch causes the transition temperature to increase by about 120 K to 160 K over the thickness reduction range of 0% to 50%.

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Dissimilar materials are inherently inhomogeneous in their material properties. Those joined by welding also contain a region affected by the heat of the welding process, which causes further non-linearity in their material properties. This paper presents the results of an investigation into the complex and combined effects of these factors on the deformation behavior and fracture strength of electron beam welded mild steel - high tensile steel plate under Mode I loading. In addition to experiments, detailed finite element analyses were carried out to resolve the stress and strain distributions in the vicinity of the crack tip and calculate the COD.

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In order to clarify the relation between strength and fracture mode, the tensile-shear test of spot welds and stress analysis has been done. The results showed that the bending moment and axial force induced by tensile-shear test affected 3 types of fracture modes (shear type fracture, plug type fracture and fracture across base metal), which depended upon the material properties, the specimen geometry, weld size, position and numbers of spot welds. As the results, the strength of spot weld changes with fracture mode.

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