Fracture toughness characterization of a PC/ABS blend under different strain rates by various J-integral methods

1996 ◽  
Vol 36 (18) ◽  
pp. 2289-2295 ◽  
Author(s):  
Ming-Luen Lu ◽  
Kuo-Chan Chiou ◽  
Feng-Chih Chang
Keyword(s):  
Fracture Toughness ◽  
Strain Rates ◽  
J Integral ◽  
Integral Methods

Fracture Toughness of PVC/NBR Blends Evaluated by the J-Integral

1993 ◽  
Vol 66 (4) ◽  
pp. 634-645
Author(s):  
N. Nakajima ◽  
J. L. Liu
Keyword(s):  
Fracture Toughness ◽  
Energy Dissipation ◽  
Crack Initiation ◽  
Crack Tip ◽  
J Integral ◽  
Integral Methods ◽  
Locus Method ◽  
Two Phases ◽  
Fracture Processes

Abstract The effect of gel on the fracture toughness of four PVC/NBR (50/50) blends was characterized by two different J- integral methods. Three of these blends are compatible blends with 33% acrylonitrile in NBRs, and the fourth with 21% acrylonitrile content, is an incompatible blend. Two types of gel are involved in this study microgels and macrogels. The J-integral methods are (1) conventional method proposed by Bagley and Landes and (2) crack initiation locus method proposed by Kim and Joe. The same load-displacement curves are used in both methods. However, the latter eliminates the energy dissipation away from the crack tip in the determination of Jc, while the former does not. Both methods produced almost the same results indicating that the energy dissipation away from the crack tip is negligible in these samples. The fracture toughness of a macrogel-containing blend is much greater than that of a microgel-containing blend, which, in turn, is only slightly greater than that of a gel-free blend. This implies that the two gel-containing blends have different fracture processes. The incompatible blend has the lowest fracture toughness due to weak interaction at the boundaries of the two phases.

Fracture toughness of high-impact polystyrene based on three j-integral methods

1993 ◽  
Vol 47 (10) ◽  
pp. 1867-1880 ◽  
Author(s):  
Chang-Bing Lee ◽  
Ming-Luen Lu ◽  
Feng-Chih Chang
Keyword(s):  
Fracture Toughness ◽  
High Impact ◽  
J Integral ◽  
High Impact Polystyrene ◽  
Integral Methods

Elastic-plastic fracture toughness of PC/ABS blend based on CTOD and J-integral methods

Polymer ◽  
1996 ◽  
Vol 37 (19) ◽  
pp. 4289-4297 ◽  
Author(s):  
Ming-Luen Lu ◽  
Kuo-Chan Chiou ◽  
Feng-Chih Chang
Keyword(s):  
Fracture Toughness ◽  
J Integral ◽  
Elastic Plastic ◽  
Integral Methods

Fracture toughness of PC/PBT blend based on J-integral methods

1995 ◽  
Vol 56 (9) ◽  
pp. 1065-1075 ◽  
Author(s):  
Ming Luen Lu ◽  
Feng-Chih Chang
Keyword(s):  
Fracture Toughness ◽  
J Integral ◽  
Integral Methods

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

Characterization of interfaces in CVD-coated nicalon fiber-reinforced SiC

1989 ◽  
Vol 47 ◽  
pp. 556-557
Author(s):  
K.L. More ◽  
R.A. Lowden
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Frictional Stress ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Carbon Coated ◽  
Fiber Matrix

The mechanical properties of fiber-reinforced composites are directly related to the nature of the fiber-matrix bond. Fracture toughness is improved when debonding, crack deflection, and fiber pull-out occur which in turn depend on a weak interfacial bond. The interfacial characteristics of fiber-reinforced ceramics can be altered by applying thin coatings to the fibers prior to composite fabrication. In a previous study, Lowden and co-workers coated Nicalon fibers (Nippon Carbon Company) with silicon and carbon prior to chemical vapor infiltration with SiC and determined the influence of interfacial frictional stress on fracture phenomena. They found that the silicon-coated Nicalon fiber-reinforced SiC had low flexure strengths and brittle fracture whereas the composites containing carbon coated fibers exhibited improved strength and fracture toughness. In this study, coatings of boron or BN were applied to Nicalon fibers via chemical vapor deposition (CVD) and the fibers were subsequently incorporated in a SiC matrix. The fiber-matrix interfaces were characterized using transmission and scanning electron microscopy (TEM and SEM). Mechanical properties were determined and compared to those obtained for uncoated Nicalon fiber-reinforced SiC.

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