Crack Wake Effects on MgO Fracture Resistance

1992 ◽  
pp. 305-317 ◽  
Author(s):  
J. LLorca ◽  
T. Ogawa
Keyword(s):  
Fracture Resistance ◽  
Crack Wake ◽  
Wake Effects

The influence of heat treatment on the fiber/matrix interface in a SiC-reinforced glassceramic

1988 ◽  
Vol 46 ◽  
pp. 742-743
Author(s):  
E. Bischoff ◽  
O. Sbaizero
Keyword(s):  
Heat Treatment ◽  
Aluminum Silicate ◽  
Lithium Aluminum ◽  
Interfacial Region ◽  
Specimen Preparation ◽  
Crack Wake ◽  
Pull Out ◽  
Annealed Material ◽  
Ultrasonic Drilling ◽  
Fiber Matrix Interface

Fiber or whisker reinforced ceramics show improved toughness and strength. Bridging by intact fibers in the crack wake and fiber pull-out after failure contribute to the additional toughness. These processes are strongly influenced by the sliding and debonding resistance of the interfacial region. The present study examines the interface in a laminated 0/90 composite consisting of SiC (Nicalon) fibers in a lithium-aluminum-silicate (LAS) glass-ceramic matrix. The material shows systematic changes in sliding resistance upon heat treatment.As-processed samples were annealed in air at 800 °C for 2, 4, 8, 16 and 100 h, and for comparison, in helium at 800 °C for 4 h. TEM specimen preparation of as processed and annealed material was performed with special care by cutting along directions having the fibers normal and parallel to the section plane, ultrasonic drilling, dimpling to 100 pm and final ionthinning. The specimen were lightly coated with Carbon and examined in an analytical TEM operated at 200 kV.

Micromechanics Measurements Applied to Integrated Circuit Microelectronics

1997 ◽  
Vol 473 ◽  
Author(s):  
David R. Clarke
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Fracture Resistance ◽  
Interface Fracture ◽  
New Techniques ◽  
Fracture Properties ◽  
Engineered Structures ◽  
Mechanical And Fracture Properties ◽  
Interconnect Lines ◽  
Metallic Interconnect

ABSTRACTAs in other engineered structures, fracture occasionally occurs in integrated microelectronic circuits. Fracture can take a number of forms including voiding of metallic interconnect lines, decohesion of interfaces, and stress-induced microcracking of thin films. The characteristic feature that distinguishes such fracture phenomena from similar behaviors in other engineered structures is the length scales involved, typically micron and sub-micron. This length scale necessitates new techniques for measuring mechanical and fracture properties. In this work, we describe non-contact optical techniques for probing strains and a microscopic “decohesion” test for measuring interface fracture resistance in integrated circuits.

Retrieval of fractured Endodontic Instrument under dental operating microscope using ultrasonic tips : A Case Report

2020 ◽  
Vol 11 (3) ◽  
pp. 3316-3321
Author(s):  
Samrudhi Khatod ◽  
Anuja Ikhar ◽  
Pradnya Nikhade ◽  
Manoj chandak
Keyword(s):  
Case Report ◽  
Root Canal ◽  
Fracture Resistance ◽  
Root Canal Treatment ◽  
Operating Microscope ◽  
Severe Loss ◽  
Mechanical Procedure ◽  
Root Dentin ◽  
Fracture Level

A Patient came with the complaint of pain in the lower right back region of the jaw. Root canal treatment was planned. While preparing for the bio-mechanical procedure, the Hand pro taper fractured in the apical third. Iatrogenic occurred as a result of the fracture of the endodontic instrument. Retrieval of the fractured instrument was planned to complete the cleaning and shaping of the canal. The removal of the fractured instrument was planned to be done under the Dental Operating Microscope. The use of an operating microscope enhanced the illumination and the magnification of the instrument. This illumination and magnification helped in the precision of removal. The ultrasonic tip enabled to reach of the fractured instrument in the canal and loosen the dentin around the fractured instrument. It allowed easy retrieval of the fractured instrument. During the retrieval procedure, the fractured instrument was bypassed before the use of the ultrasonic tip. After the removal of the fractured instrument, cleaning and shaping were completed, followed by obturation, definitive restoration, and prosthesis. As the removal of the fractured instrument enabled complete cleaning and shaping, it improved the prognosis of the case. When the endodontic instrument gets fractured, it should be analyzed over the radiograph to assess the fracture level, the anatomy of the root canal, size of the fractured instrument, check accessibility, stage of fracture, etc. If all the above criteria are met with the removal of the instrument only then, replacement should be tried. Otherwise, it may lead to a severe loss of root dentin, decreasing fracture resistance of the root.

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