SPIRAL TUNNELING CRACKS INDUCED BY ENVIRONMENTAL-STRESS CRACKING IN LARC(TM)-TPI ADHESIVES

被引：15

作者：

DILLARD, DA ^{[1
]}

HINKLEY, JA ^{[1
]}

JOHNSON, WS ^{[1
]}

CLAIR, TLS ^{[1
]}

机构：

[1] NASA,DIV MAT,HAMPTON,VA 23686

来源：

JOURNAL OF ADHESION | 1994年 / 44卷 / 1-2期

基金：

美国国家科学基金会;

关键词：

SPIRAL CRACKS; ADHESIVES; COATINGS; LARC-TPI; POLYIMIDE; ENVIRONMENTAL STRESS CRACKING; RESIDUAL STRESSES; TUNNEL CRACKS;

D O I：

10.1080/00218469408026616

中图分类号：

TQ [化学工业];

学科分类号：

0817 ;

摘要：

Some currently-available formulations of LaRC(TM)-TPI, a thermoplastic polyimide originally developed at NASA-Langley, were found to be highly susceptible to environmental stress cracking when exposed to solvents such as acetone, toluene, diglyme and methyl ethyl ketone. The combination of stress and solvent led to rapid cracking in films and adhesive layers of this material system. Residual cool-down stresses induced when the LaRC-TPI is used as an adhesive or coating led, in the presence of a solvent, to dense ''mud crack'' patterns which relieve a portion of the stored energy. Because these through-the-thickness cracks are not able to relieve the stored energy in the vicinity of the adherends, additional fractures in the form of curious spiral tunnel cracks initiated and grew inward within each adhesive fragment. Micrographs of the spiral fractures are given, along with a qualitative explanation for the failure process as observed in adhesives and coatings.

引用

页码：51 / 67

页数：17

共 22 条

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