The main aim of this research was to find the mechanism for the failure of the CoCrMo porous nano-composite by characterizing microstructural changes and fractured surface after compression test. For this purpose, porous nano-composites were prepared with the addition of bioactive glass nano-powder to Co-base alloy with 22.5% porosity by the combination of space-holder and powder metallurgy tec...

In this paper dynamic fracture process due to high-speed impact of steel plunger into ceramic sample is simulated. The developed numerical model is based on finite element method and a concept of incubation time criterion, which is proven to be applicable in order to predict brittle fracture under high-rate deformation. Simulations were performed for ZrO2(Y2O3) ceramic plates. To characterize f...

objective: introduction of fiber-reinforced composites (frc) greatly enhanced the restoration of fractured anterior teeth. the purpose of this study was to assess the effect of fiber reinforcement on fracture resistance of incisal edge composite restorations of variable thicknesses. methods: forty extracted sound human maxillary incisors were divided into four groups of 10. incisal reduction wa...

This paper presents a failure analysis on a failed intake valve in a gasoline engine. During an endurance test, an intake valve was broken and caused some damages on the piston. Material examinations (by a light microscope and also a scanning electron microscope) were conducted on the fracture surface of the intake valve shaft. Results showed that no pores or defects could be observed and the m...

In this paper a new method to determine the fracture properties and strain energy release rate for Carbon- Polyester composite has been introduced.  Fracture characteristics such as critical stress intensity factor and critical strain energy release rate for mode I, mode II and mixed mode loading were determined using Arcan type specimen. 130 layers of carbon fiber polyester woven composite wit...

1. Problem formulation. The processes governing the fracture of brittle solids are, at present, much less illuminated than those related to plastic deformations. The reason is that it is very difficult to observe the detailed fracture process directly. All one can determine is the load, which acted immediately before fracture started, and the path and nature of the fracture surface. Because dur...

magnesium alloys in liquid-phase condition form surface oxide films due to their high rate of oxidation. oxide films enter the melt as a result of surface turbulence, and remain inside the workpiece after solidification. the incoherent nature of their interface causes decreases in mechanical properties and reliability of castings. the effect of critical velocity and greater velocities of enteri...

Objective: Introduction of fiber-reinforced composites (FRC) greatly enhanced the restoration of fractured anterior teeth. The purpose of this study was to assess the effect of fiber reinforcement on fracture resistance of incisal edge composite restorations of variable thicknesses. Methods: Forty extracted sound human maxillary incisors were divided into four groups of 10. Incisal reduction wa...

As part of a study of the cell surface changes associated with the production of murine mammary tumor virus, the structure of the envelope of this virus has been examined by using freeze-fracture techniques. Both fracture and deep-etch surfaces were examined. The fracture faces contain 10-nm spheres comparable to those observed on fractured plasma membranes, although fewer in number. Surfaces e...