Introduction

This section of the site addresses how IPA and PCA technology can be used against a number of material conditions. This section will be updated frequently as more experience is gained.

Inclusions

	Results & Impediments
The presence of metallic or non-metallic inclusions can result in material failure during the metal forming process or lead to a serious deterioration in the quality of the final product. The effect becomes more critical for exceptionally high grade metals used in critical industry applications. Many studies have worked with inclusions down to two or three microns in size, however smaller inclusions can also cause problems, especially if a number of them are close and produce a 'pile-up' effect.	cracking and pores around the inclusion / metal join inclusions slow the recrystallization process inclusions can prevent recrystallization
	Uses	Benefits
Positron's IPA and PCA technologies can detect inclusions to a resolution of a few nanometers (about 100x better than current techniques).	inspection for inclusions quality control of manufacturing processes	higher confidence in quality reduced catastrophic failures

Hydrogen Embrittlement

	Results & Impediments
Hydrogen Embrittlement of metals, especially HSLA steels, poses a difficult inspection problem for engineers. Often times, this problem is unknown until a component fails unexpectedly. There are few viable non-destructive test options available. Furthermore, sustained load testing is a time consuming process, which can make verification of mitigation efforts in real time impossible.	Parts rejected at a late stage of manufacturing Catastrophic component failure
	Uses	Benefits
IPA has been shown to be able to detect the presence of hydrogen in a material. This can allow a nondestructive quality check to ensure hydrogen mitigation efforts have been successful.	Quality Control inspection	Quicker Non destructive

Residual Stress

	Results & Impediments
Inducing compressive residual stresses at areas of stress concentration can be one of the most cost effective methods to mitigate fatigue damage in components. Effective use of compressive residual stress can increase fatigue life by a factor of three. Failure to properly impart this stress state can result in premature failures of components and it can be difficult to verify that the technique used was successful. Almen Strips, used to quantify shot peening processes are separate from the area of interest on a part. X-Ray diffraction, the current NDE state of the art for residual stress, is hampered by low penetration depths, complex procedures, and difficulties in some materials.	Unexpected premature failure Expensive, limited QC availability
	Uses	Benefits
IPA can quantify residual stress with deeper penetration and easier setup. Residual stress state can be verified via direct measurement of the part.	Quality Control inspection	Quick Easier Setup Measure the part itself

Fatigue

	Results & Impediments
Fatigue is a major design driver in many industries. Designs where fatigue is a factor must either have a conservative life estimate or require periodic inspections for cracks. The conservative life estimates of critical safe life parts means that virtually all parts that are replaced for reaching an end of life criteria have remaining life. Inspections of damage tolerant design parts require a crack of a certain length. Thus, inspectable crack length drives inspection interval; each inspection requires removal from service and often costly teardown.	Replacement of capable part Frequent inspections Damage appears suddenly
	Uses	Benefits
Positron’s IPA technology can track fatigue damage over a component’s life, even before a crack initiates. Remaining life can be reassessed for safe life parts, and inspection intervals can be extended on damage tolerant parts. PCA technology allows inspection for cracks, but with greater resolution and with reduced teardown.	IPA - Track damage over life part PCA - Inspection for existing fatigue	Remaining life is assessed from the damage state of the material Increased resolution Decreased teardown

Undesirable Material Phase

	Results & Impediments
In some metallic materials, undesirable material phases can develop during manufacturing that undermine the desired properties of the material. Examples include alpha case in titanium castings and sigma phase in duplex stainless steels. Non destructive testing for these phases is in many cases virtually impossible with current NDE techniques.	Unexpected failure
	Uses	Benefits
IPA can detect the different microstructure of undesirable phases, allowing for a non-destructive evaluation of manufacturing and heat treatment techniques. This reduces dependence on destructive testing of process samples, as measurement is of the part.	Quality Control of processes	Reduced test time Test on part itself

Defects in Composite Materials

	Results & Impediments
There are currently few viable methods to non-destructively inspect composite materials. Often, composite materials are not optimized to their design potential because designers must make allowances for defects and damage. Impact and fatigue can result in delaminations below the surface, invisible to inspectors, which can impact structural integrity. Manufacturing induced defects such as porosity, resin rich areas, and foreign materials can result in a final product below a designer’s expectations	Overdesign Unexpected failure
	Uses	Benefits
PCA promises to revolutionize the composites industry by providing accurate and detailed images of composite structures. Internal defects and damage, which is undetectable by current techniques, can be seen. This means that unnecessary over design is a thing of the past and removal from service due to suspected damage will no longer be necessary.	Inspection of composite materials	Only viable option for many defects