In order to evaluate the influence of sheet electron beam irradiation (SEBI) with low potential on water absorption in nylon6, the mass of water absorption in nylon6 has been measured. The SEBI decreases the saturated mass of water absorption in nylon6 and also decreases the initial absorption rate of water, as well as the mass of absorbed water in nylon6 for each treatment time. Based on the results of ESR and XPS, the SEBI forms dangling bonds and then decreases the electrical polarization of nylon6 molecules, resulting in decreasing the mass of absorbed water in nylon6.

Composite polymers, which are Nylon6 matrix homogeneously dispersed with aluminum powders, are prepared. To evaluate the brittleness, Charpy impact values are obtained. Although an aluminum addition of 10 vol tremendously decreases the impact value, excess aluminum additions from 30 to 40 vol don't largely decrease the impact value. It is explained that cracks easily propagate through the interface between the aluminum powders and polymer matrix because of the weak interface.

Effects of silane coupling treatment and electron beam (EB) irradiation on bending test of glass fiber reinforced epoxy polymer (GFRP) thick sheet were studied. EB irradiation increased the bending strength and its strain of GFRP thick sheet with silane coupling treatment. EB irradiation also enhanced the apparent hardening modulus (ds/de) of bending deformation and increased the deformation energy of GFRP thick sheet with silane coupling treatment. The deformation energy depends on the strain improvement at the maximum bending stress of epoxy resin and glass fiber and the interfacial friction force.

Carbon fiber reinforced polymer (CFRP) had recently been applied to not only wing, but also fan blades of turbo fan engines. To prevent impact force, leading edge of titanium was often mounted on the CFRP fan blades by adhesive force. In order to enhance the joining strength, we suggested a joining method with carbon fiber reinforced interface. By using nickel coated carbon fibers, we successfully developed a joining sample with carbon fiber reinforced interface between CFRP and CFRM. The joining sample with nickel coated carbon fiber exhibited the high tensile strength, which was approximately two times larger than that with non coated one and was also more than 11 times higher than that with conventional adhesion.

Magnetostriction and its susceptibility of Fe 3.2 Tb alloy thin film deposited on polyurethane rubber substrate with low deformation resistance by using direct current magnetron sputtering process were investigated. When both residual gas pressure before argon sputtering and sputtering pressure of argon gas (5 N) were less than 5.0×10 -4 Pa and 2.0×10 -1 Pa, respectively, the thickness of the Fe 3.2 Tb films deposited was about 2.96 mm. The giant magnetostriction was found in the Fe 3.2 Tb alloy film on polyurethane rubber sheet, rather than on other polymer sheets. Giant motion strain of Fe 3.2 Tb alloy film largely depended on deformation resistance of substrate. (Received December 25, 2007; Accepted March 18, 2008) Keywords: magnetostriction, susceptibility, mover film, terbium, iron, direct current magnetron sputtering 緒 言