Accession Number : ADA127402


Title :   Titanium Matrix/Continuous Fiber Composite Interface Interactions and their Influence on Mechanical Properties.


Descriptive Note : Annual technical rept. 1 Jan-31 Dec 82,


Corporate Author : TEXAS UNIV AT AUSTIN MATERIALS SCIENCE AND ENGINEERING


Personal Author(s) : Marcus,Harris L


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a127402.pdf


Report Date : 25 Feb 1983


Pagination or Media Count : 74


Abstract : The effect of the fatigue crack growth behavior of the SiC and B4C/B reinforced titanium-6 aluminum-4 vanadium metal matrix composites by the modification of the interface between the fiber and the matrix by isothermal and thermal fatigued treatments was studied. The thermal cycling and isothermal treatments were carried out in environments of vacuum, air and sulfur. One and two dimensional analysis of sulfur and oxygen diffusion indicated that the interface has a thin but finite thickness and is a high diffusion path for sulfur and oxygen. Thermal cycling treatment enhanced the interface diffusion. The fatigue crack growth results demonstrated that the interface transferred the load during fatigue cycling in either an invert environment or if the interface has a minimal amount of impurities. In the case of the sulfur enriched interface the humid air, FCG environment reduced the cohesion of the interface with the load totally carried by the matrix. This led to an increased FCG range with a higher value of the Paris exponent. Without the enhanced sulfur at the interface the Paris exponent remained constant although the fatigue crack growth rate in dry hydrogen was lower than in the humid air but greater than in dry nitrogen for all conditions.


Descriptors :   *MECHANICAL PROPERTIES , *COMPOSITE MATERIALS , *MATRIX MATERIALS , *TITANIUM , METALS , INTERACTIONS , INTERFACES , FIBER REINFORCED COMPOSITES , FRACTURE(MECHANICS) , OXYGEN , CRACK PROPAGATION , TABLES(DATA) , ENVIRONMENTAL TESTS , FATIGUE(MECHANICS) , THERMAL FATIGUE , DIFFUSION , SULFUR , SILICON CARBIDES , ISOTHERMS , TITANIUM ALLOYS , VANADIUM , COHESION , FACTOR ANALYSIS


Subject Categories : Laminates and Composite Materials
      Metallurgy and Metallography
      Mechanics


Distribution Statement : APPROVED FOR PUBLIC RELEASE