Author: Christopher Joseph GilbertPublisher:
ISBN:
Category :
Languages : en
Pages : 618
Book Description
Ambient and Elevated Temperature Fracture and Cyclic-fatigue Properties of in Situ Toughened Ceramics
Author: Christopher Joseph GilbertPublisher:
ISBN:
Category :
Languages : en
Pages : 618
Book Description
Ambient and Elevated Temperature Fracture and Cyclic-fatigue Properties in a Series of Al-containing Silicon Carbides
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 86
Book Description
A series of in situ toughened, Al, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with Al contents varying from 3 to 7 wt%. With increasing Al additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline. Fracture toughness and cyclic fatigue tests on these microstructures revealed that although the 7 wt.% Al containing material (7ABC) was extremely brittle, the 3 and particularly 5 wt.% Al materials (3ABC and 5ABC, respectively) displayed excellent crack-growth resistance at both ambient (25 C) and elevated (1300 C) temperatures. Indeed, no evidence of creep damage, in the form of grain-boundary cavitation, was seen at temperatures at 1300 C or below. The enhanced toughness of the higher Al-containing materials was associated with extensive crack bridging from both interlocking grains (in 3ABC) and uncracked ligaments (in 5ABC); in contrast, the 7ABC SiC showed no such bridging, concomitant with a marked reduction in the volume fraction of elongated grains. Mechanistically, cyclic fatigue-crack growth in 3ABC and 5ABC SiC involved the progressive degradation of such bridging ligaments in the crack wake, with the difference in the degree of elastic vs. frictional bridging affecting the slope, i.e., Paris law exponent, of the crack-growth curve. In addition an investigation of fracture resistance in non-transforming ceramics toughened by grain bridging mechanism is presented using linear elastic fracture mechanics (LEFM). Linear superposition theorems are used for the superposition of crack opening displacements, as well as stress intensity factors, resulting from the external tractions and the internal compressive bridging stresses. Specifically weight functions are used to relate the CODs, stress intensity factors, and tractions and the bridging stress. Expressions are derived for apparent material resistance, the bridging resistance and the intrinsic toughness, and an experimental procedure is proposed by which these predictions can be verified.
Ambient and Elevated Temperature Fracture and Cyclic-fatigue Properties of Boron-modified Molybdenum Silicides
Author: Heeman ChoeAmbient and Elevated Temperature Fracture and Cyclic-fatigue Properties in a Series of Al-containing Silicon Carbide Ceramics
Author: Rong Yuan (M.S.)Ambient and Elevated Temperature Fracture and Cyclic-fatigue Properties in a Series of A1-containing Silicon Carbide Ceramics
Author: Jung YüanAmbient to High-temperature Fracture Toughness and Cyclic Fatigue Behavior in Al-containing Silicon Carbide Ceramics
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 5
Book Description
A series of in situ toughened, A1, B and C containing, silicon carbide ceramics (ABC-SiC) has been examined with A1 contents varying from 3 to 7 wt percent. With increasing A1 additions, the grain morphology in the as-processed microstructures varied from elongated to bimodal to equiaxed, with a change in the nature of the grain-boundary film from amorphous to partially crystalline to fully crystalline.
Handbook of Advanced Ceramics
Author: Tatsuki OhjiPublisher: Elsevier Inc. Chapters
ISBN: 0128057343
Category : Technology & Engineering
Languages : en
Pages : 65
Book Description
Fracture Mechanics of Ceramics
Author: R.C. BradtPublisher: Springer Science & Business Media
ISBN: 1461558530
Category : Technology & Engineering
Languages : en
Pages : 591
Book Description
Second part of the proceedings of the Sixth International Symposium held in Karlsruhe, Germany, July 18-20, 1995.
High-temperature Cyclic Fatigue and Fracture Properties in Silicon Nitride Structural Ceramics
Author: Alexander ZieglerMechanical Properties of Ceramics
Author: John B. WachtmanPublisher: Wiley
ISBN: 0470451505
Category : Technology & Engineering
Languages : en
Pages : 496
Book Description
A Comprehensive and Self-Contained Treatment of the Theory and Practical Applications of Ceramic Materials When failure occurs in ceramic materials, it is often catastrophic, instantaneous, and total. Now in its Second Edition, this important book arms readers with a thorough and accurate understanding of the causes of these failures and how to design ceramics for failure avoidance. It systematically covers: Stress and strain Types of mechanical behavior Strength of defect-free solids Linear elastic fracture mechanics Measurements of elasticity, strength, and fracture toughness Subcritical crack propagation Toughening mechanisms in ceramics Effects of microstructure on toughness and strength Cyclic fatigue of ceramics Thermal stress and thermal shock in ceramics Fractography Dislocation and plastic deformation in ceramics Creep and superplasticity of ceramics Creep rupture at high temperatures and safe life design Hardness and wear And more While maintaining the first edition's reputation for being an indispensable professional resource, this new edition has been updated with sketches, explanations, figures, tables, summaries, and problem sets to make it more student-friendly as a textbook in undergraduate and graduate courses on the mechanical properties of ceramics.