In this study, we investigate the effect of the duration of mechanical alloying on the microstructures and mechanical properties of ODS ferritic/martensitic steel. The Fe(bal.)-10Cr-1Mo pre-alloyed powder and Y2O3 powder are mechanically alloyed for the different mechanical alloying duration (0 to 40 h) and then constantly fabricated using a uniaxial hot pressing process. Upon increasing the mechanical alloying time, the average powder diameter and crystallite size increased dramatically. In the initial stages within 5 h of mechanical alloying, inhomogeneous grain morphology is observed along with coarsened carbide and oxide distributions; thus, precipitate phases are temporarily observed between the two powders because of insufficient collision energy to get fragmented. After 40 h of the MA process, however, fine martensitic grains and uniformly distributed oxide particles are observed. This led to a favorable tensile strength and elongation at room temperature and 650oC.

Alloy 617, Ni-22Cr-12Co-9Mo base oxide dispersion strengthened alloy was fabricated by using mechanical alloying, hot isostatic pressing and hot rolling. Uniaxial tensile tests were performed at room temperature and at . Compared with the conventional Alloy 617, ODS alloy showed much higher yield strength and tensile strength, but lower elongation. Fracture surfaces of the tensile tested specimens were investigated in order to find out the mechanism of fracture mode at each test temperature. Grain adjustment during tensile deformation was analyzed by electron backscattered diffraction mapping, inverse pole figures and TEM observation.

The study was conducted to evaluate reliability of the longitudinal tensile properties of unidirectional carbon fiber reinforced composites. Two kinds of carbon fiber reinforced composites laminates were tested in order to examine the factors of variability and have the information concerning reliability improvement. Temperature dependence of the strength and its variability were investigated by means of testing at two kinds of temperatures. Statistical distributions of the respective mechanical properties were obtained from the tensile tests. As a result, strength of composites was directly proportional to the ultimate strain and was not proportional to the elastic modulus. The fracture behavior in bending of notched plate was studied for a composite material. The uniform bending tests of notched plates have been carried out for a wide range of notch radii. The experiment shows that the nominal stress at failure decreased with decreasing notch radius and it approaches a constant value when the notch radius is less than about 0.3mm. The critical maximum stress is governed by notch root radius alone in the case of a constant thickness of specimen.

CFRP (Carbon Fiber Reinforced Plastic) has high tensile strength, light weight, and excellent corrosion resistance, so it is used for construction such as seismic reinforcement and explosion proof in construction area. Dynamic loads, such as earthquakes and explosions, cause rapid deformation of the material and the material behaves differently from its static condition. Therefore, in this study, tensile tests of CFRP were conducted under static and dynamic loads, and the tensile performance of was evaluated according to the strain rate.