FAILURE ANALYSIS AND MATERIALS TESTING

An Introduction

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Failure Analysis

Task: To investigate the different types of failures

Objective: To understand the cause(s) of failure

Significance: To take measures that can prevent them in the future

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Definition

Failure Analysis is an investigation carried out to determine the cause of failure of a certain product or equivalently the mistake in the continuous process of engineering design-manufacturing-performance in order to prevent its recurrence in the future.

Failure Analysis

Procedure involves a series of examinations to reveal:

-Quality of the material

-Quality of the fabrication process

-Possible abuse during service

Failure Analysis is Designed to:

1. Identify the Failures Modes

- the way the product failed

2. Identify the Failure Site

- where in the product failure occurred

3. Identify the Failure Mechanism

- the physical phenomena involved in the

failure

4. Determine the Root Cause

- the trigger point which led to failure

5. Recommend Failure Prevention Methods

- corrective action or improvement

Failure Analysis is Designed to:

Failure Analysis7

Manufacturing/Production

FA

Tools and Techniques

Aid in analyses of rejects

Understand root cause(s) of failure

Fails/Rejects

DRIVE customer returns tozero, INCREASE quantityand quality, ACCELERATEnew product introductions

Results

Engineering Products and their Performance

Main Stages in theHistory of anEngineering Product

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Engineering Design

Manufacturing(Commercial Product)

Service Conditions(Performance)

Engineering Products and their Performance9

Almost every design and useful application devised by the engineer is dictated by the quality of materials used in manufacturing, which limits the performance capabilities of the product.

Engineering Design-Fabrication-Performance

Schematic illustration of the continuity and main steps of the process of engineering design–manufacturing–performance

Lifetime of a given product can vary significantly depending

upon variables such as:

(i) the extent of analysis and experimental development

involved in the various stages of design

(ii) the quality of materials used to manufacture the product

(iii) manufacturing technology

(iv) exact knowledge of service conditions

Engineering Design-Fabrication-Performance

Materials Selection

.

Materials Selection is governed:

(i) properties relevant to the application

(ii) manufacturing constraints

(iii) effect of manufacturing procedures on properties

(iv) prior incidents of failure

(v) maintenance and repair frequency

(vi) cost

Property Evaluation

It is possible to evaluate the properties of a failed component by

two main types of tests:

(i) nondestructive

(ii) destructive.

Nondestructive tests do not degrade the integrity of the component

being tested and primarily carried out to detect flaws and control

dimensions.

Destructive tests are used to determine certain properties, which

are mostly of mechanical nature, such as tensile strength, creep

strength, and fatigue strength.

FA TECHNIQUES

Non-destructive FA Techniques

optical microscopy (external or internal visual inspection)

x-ray radiography (internal x-ray imaging)

curve tracing (current-voltage characterization)

SAM (detection of delamination)

Liquid dye penetrant (detecting cracks at the surface)

Magnetic particle inspection (surface flaws in magnetic materials)

Ultrasonic inspection (flaw detection and thickness measurement)

FA TECHNIQUES

Destructive FA techniques

decapsulation (opening of the IC package)

sectioning (cross-sectioning of the sample)

SEM/TEM (high magnification real-time imaging)

EDX/WDX (uses x-ray for elemental analysis)

mechanical testing (hardness and mechanical testing)

Auger analysis (surface analysis)

Quiz #1

1. What are the three stages of the history of an engineering product?

2. Give 3 examples of non-destructive FA techniques.

3. Give 3 examples of destructive FA techniques.

4. Failure analysis is sometimes called __________.

THE End.

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