Method of proving the quality of a bond

Patent metadata

Field	Value
Publication number	US-9604403-B1
Application number	US-201615015518-A
Country	US
Kind code	B1
Filing date	Feb 4, 2016
Priority date	Feb 4, 2016
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A method of assessing bond quality of a bond between first and second composite parts may include bonding an indication film to the first composite part. The indication film may include NDI-detectable particles arranged in a pattern and bound to polymer chains located inside particle regions. The polymer chains and particles may be stationary during bonding of the indication film to the first composite part. The method may additionally include bonding the first and second composite parts along an assembly bondline during which the particles in the indication film migrate with the polymer chains. The method may further include NDI-inspection of the assembly bondline by observing the appearance of the particles along a direction locally normal to an in-plane direction of the assembly bondline, and determining the bond quality of the assembly bondline based on particle density in the in-plane direction.

First claim

What is claimed is:

1. A method of assessing bond quality of a bond between a first composite part and a second composite part of a structural assembly, comprising the steps of:
bonding an indication film to a first composite part, the indication film being comprised of polymer chains and including particles arranged in a pattern of particle regions, the particles being bound to the polymer chains located inside the particle regions to define tagged polymer chains and being detectable by non-destructive inspection, the tagged polymer chains and particles being stationary during bonding of the indication film to the first composite part;
applying the first composite part to a second composite part along an assembly bondline;
bonding the first composite part to the second composite part along the assembly bondline during which the particles in the indication film migrate with the tagged polymer chains;
inspecting, using a non-destructive inspection (NDI) technique, the assembly bondline by observing an appearance of the particles along a direction substantially locally normal to an in-plane direction of the assembly bondline; and
determining a bond quality of the assembly bondline based on particle density in the in-plane direction.

2. The method of claim 1 , wherein the step of determining the bond quality in the assembly bondline includes:
measuring a variation in particle density in an in-plane direction of the assembly bondline.

3. The method of claim 1 , wherein the step of determining the bond quality in the assembly bondline comprises:
comparing an NDI image of the assembly bondline of the structural assembly to a reference image of an assembly bondline of a reference standard of the structural assembly.

4. The method of claim 1 , wherein the step of inspecting, using an NDI technique, the assembly bondline comprises:
imaging the assembly bondline using at least one of eddy current testing, magnetic-particle inspection, thermography, color x-ray, and computerized tomography.

5. The method of claim 1 , wherein the step of bonding the indication film to the first composite part comprises bonding a first indication film to the first composite part, the first indication film including particles arranged in a first pattern, the method further including:
bonding a second indication film to the second composite part, the second indication film having a second pattern that is different than the first pattern in the first indication film;
applying the first composite part to the second composite part such that the respective first and second indication films are in contacting relation with one another along the assembly bondline; and
bonding the first composite part to the second composite part along the assembly bondline, the particles in the first and second indication films migrating with the tagged polymer chains during the bonding of the first composite part to the second composite part due to miscibility of the polymer chains in the first and second indication films.

6. The method of claim 1 , further comprising:
heating the assembly bondline during the bonding of the first composite part to the second composite part.

7. The method of claim 1 , wherein:
the first composite part is uncured prior to bonding to the indication film; and
the step of bonding the indication film to the first composite part comprises curing the first composite part while bonding the indication film to the first composite part.

8. The method of claim 1 , wherein:
at least one of the first composite part and second composite part is uncured prior to bonding the first composite part to the second composite part.

9. The method of claim 1 , wherein at least one of the first composite part and second composite part has one of the following initial configurations prior to bonding to an indication film and prior to bonding to one another:
a prepreg composite laminate containing at least one prepreg composite ply; and
a dry fiber preform configured to be infused with resin.

10. The method of claim 1 , wherein the first composite part and the second composite part have one of the following material combinations:
the first composite part and the second composite part are both thermosets;
the first composite part and the second composite part are both thermoplastics; and
one of the first composite part and the second composite part is a thermoset and a remaining one of the first composite part and the second composite part is a thermoplastic.

11. The method of claim 1 , wherein:
the indication film is at least partially comprised of thermoplastic material.

12. The method of claim 1 , wherein:
the particles are bound to the polymer chains by at least one of covalent bonding, ionic bonding, and hydrogen bonding.

13. The method of claim 1 , wherein:
the particles are nanoparticles that are covalently bonded to the polymer chains using a silane coupling agent.

14. The method of claim 1 , wherein:
the particles are at least one of the following: magnetic nanoparticles, particles formed of high-Z materials including at least one of iron oxide, gold, nickel, cobalt, and silicon.

15. The method of claim 1 , wherein:
the particles in the pattern are arranged in particle regions having at least one of the following shapes: circles, squares, rectangles, triangles, polygons, stars, crescents, straight stripes, and curved stripes.

16. The method of claim 1 , wherein:
a particle region has an in-plane width of several nanometers up to a thickness of the indication film.

17. The method of claim 1 , wherein:
the particle regions are separated from adjacent particle regions by a region spacing in a range of several nanometers up to a thickness of the indication film.

18. A method of assessing bond quality of a bond between a first composite part and a second composite part of a structural assembly, comprising the steps of:
bonding an indication film to each one of a first composite part and a second composite part, each indication film being comprised of polymer chains and including particles arranged in a pattern of particle regions, the particles being bound to the polymer chains located inside the particle regions to define tagged polymer chains and being detectable by non-destructive inspection, the tagged polymer chains and particles being stationary during bonding of the indication films to the respective first and second composite parts;
applying the first composite part to the second composite part such that the indication films are in contacting relation to one another along an assembly bondline;
bonding the first composite part to the second composite part along the assembly bondline during which the particles in the indication films migrate with the tagged polymer chains;
inspecting, using a non-destructive inspection (NDI) technique, the assembly bondline by observing an appearance of the particles along a direction substantially locally normal to an in-plane direction of the assembly bondline; and
determining the bond quality of the assembly bondline based on particle density in the in-plane direction.

19. The method of claim 18 , wherein:
the indication film of the first composite part has a first adhesive composition;
the indication film of the second composite part has a second adhesive composition such that the indication films form a two-part adhesive; and
the step of bonding the first composite part to the second composite part causing mixing of the first and second adhesive compositions and resulting in movemen

Assignees

• Boeing Co

Inventors

• Wilenski Mark S
• Crothers Phillip J

Classifications

• B29L2009/00

  Layered products · CPC title

• B29K2101/12

  Thermoplastic materials · CPC title

• B29C65/8253 Primary

  by the use of waves or particle radiation, e.g. visual examination, scanning electron microscopy, or X-rays (B29C65/8292 takes precedence) · CPC title

• B32B2041/04

  Detecting wrong registration, misalignment, deviation, failure · CPC title

• B32B41/00 Primary

  Arrangements for controlling or monitoring lamination processes; Safety arrangements · CPC title