Inelastic Deformation of Metal Matrix Composites


Book Description

The inelastic deformation mechanisms for the SiC (SCS-6)/Ti-15-3 system were studied at 538 C (1000 F) using a combination of mechanical measurements and detailed microstructural examinations. The objectives were to evaluate the contributions of plasticity and damage to the overall MMC response, and to compare the room temperature and elevated temperature deformation behaviors. Four different laminates were studied: (0)8, (90)8, (] or -45)2s, and (0/90)2s, with the primary emphasis on the unidirectional (0)8, and (90)8 systems. The elevated temperature responses were similar to those at room temperature, involving a two-stage elastic-plastic type of response for the (0)8 system, and a characteristic three-stage deformation response for the (90)8 and (+ or -45)2s systems. The primary effects of elevated temperatures included: (1) reduction in the 'yield' and failure strengths; (2) plasticity through diffused slip rather than concentrated planar slip (which occurred at room temperature); and (3) time-dependent deformation. The inelastic deformation mechanism for the (0)8 MMC was dominated by plasticity at both temperatures. For the (90)8 and (+ or -45)2s MMCs, a combination of damage and plasticity contributed to the deformation at both temperatures. Majumdar, B. S. and Newaz, G. M. Unspecified Center..













Mechanisms and Mechanics of Composites Fracture


Book Description

Contains 26 papers presented at the International Conference on [title], held to address the latest ideas concerning the mechanisms and mechanics of composite fractures. The main focus was on the "driving forces" behind the various damage events in the inorganic composites at both micro and macro levels. The papers are grouped in five sections: deformation and damage in particulate composites; crack initiation and propagation; micromechanical modeling; fracture and fatigue; and microstructural tailoring, impact, and creep. No index. Annotation copyright by Book News, Inc., Portland, OR




Metal Matrix Composites


Book Description







Isothermal Fatigue Mechanisms in Ti-based Metal Matrix Composites


Book Description

Stress-controlled isothermal fatigue experiments were performed at room temperature (RT) and 548 C (in argon) on (0)8 SCS6/Ti 15-3 metal matrix composites (MMC's) with 15 and 41 volume percent SCS6 (SiC) fibers. The primary objectives were to evaluate the mechanical responses, and to obtain a clear understanding of the damage mechanisms leading to failure of the MMC's. The mechanical data indicated that strain ranges attained fairly constant values in the stress-controlled experiments at both RT and 538 C, and remained so for more than 85 percent of life. The fatigue data for MMC's with different volume fraction fibers showed that MMC life was controlled by the imposed strain range rather than the stress range. At RT, and at low and intermediate strain ranges, the dominant fatigue mechanism was matrix fatigue, and this was confirmed metallurgically from fractographic evidence as well as from observations of channel type dislocation structures in the matrix of fatigued MMC specimens.




Life Prediction Methodology for Titanium Matrix Composites


Book Description

Papers presented at the March 1994 symposium are organized into five sections that progress from basic understanding of mechanical damage mechanisms and environmental effects to life prediction methodology. Five papers discuss the interplay between interfacial strength, residual thermal stresses, an




Titanium Matrix Composites


Book Description

A review and summary of advancements related to mechanical behavior and related mechanics issues of titanium matrix composites (TMCs), a class of high-temperature materials useful in the propulsion and airframe components in advanced aerospace systems. After an introduction to TMCs, different authors review and summarise the advancements related to mechanical behavior and related mechanics issues of TMCs.