Testing/Failure Analysis Course

Fracture Analysis Toolbox

COURSE OUTLINE:

•  What is a crack? What is a fracture? Crack type classification systems.

•  Getting Set up for a Fracture Analysis: Dangers of rushing, following orders, what physical actions are required (and why) in a failure analysis

•  Review of mechanical properties (tensile and yield strengths, modulus of elasticity, elongation, hardness, Charpy impact, fracture toughness, creep and stress relaxation) and their importance in understanding the fracture process

•  Crash course in principles of materials science and engineering (atoms, crystallography, anisotropy, relationship of material properties to process and microstructure)

•  The Toolbox: Visual Evaluation/Macro Fractography/ Specimen Selection; Proper Specimen Preservation, Replication, and Cleaning; Specimen, Cutting and Preparation, microfractography (SEM); Microchemical analysis (EDS); Mechanical Tests-What they do and do not tell you; Bulk composition analysis-What it does and does hot tell you; Metallography and Microstructures; Comments on the importance of stress analysis-intuitive and numerical; Specimen selection activity

•  Crash Course in Phase Diagrams, CCC, and Jominy data interpretation

•  Special Comments on Mechanical properties of importance, correlation of other mechanical properties with hardness tests-what can and can't be obtained monotonic and cyclic loading

•  Introduction to elementary stress analysis and states of stress

•  Understanding Macrofractography

•  Student Exercise: Part examination

•  Case Histories

 

COURSE OVERVIEW:

The purpose of this course is to help the participant improve their fracture analysis skills. The course will cover the main conceptual and instrumental "Tools of the Fracture Analysis Trade."

Students are welcome to bring parts or reports that theyhave, which we may discuss as time allows.

WHO SHOULD ENROLL:

This is a practical hands on class focused toward people who are relatively new to a comprehensive approach to failure analysis. There will be hands on laboratory experiences (hardness determination, microstructure evaluation, macro fractography).

 

Fundamentals of NONDESTRUCTIVE TESTING

 

COURSE OUTLINE

•  Introduction to Nondestructive Testing : principles; test systems; applications; transducers; radiation; magnetic properties; glossary

•  Liquid Penetrants: principles; materials; processing cycles; applications; limitations

•  Magnetic Particle Inspection Fundamentals: magnetism; testing principles; inducing magnetic fields; methods; materials; equipment; demagnetization

•  Magnetic Particle Inspection Applications: method selection; effect of magnetic field direction; conducting test; demagnetization; interpretation of results

•  Ultrasonic Testing Fundamentals: wave propagation and properties; reflection-refraction; mode conversion; diffraction attenuation; ultrasound generation and reception; crystal transducer

•  Ultrasonic Testing Equipment: piezoelectric crystals; use; transducers; generator/indicator equipment; standards; accessories

•  Ultrasonic Testing Applications: method selection; applications of various methods; metallurgical structures; calibration; standards

•  Radiography Fundamentals I : principles; radiation sources; characteristics of radiation; exposure variables; screen scattering; films

•  Radiography Fundamentals II: method selection; safety; interpretation; penetrameters; specifications; typical discontinuities

•  Eddy Current Fundamentals: electromagnetic currents; impedance plane diagrams; magnetic permeability; coils; instrumentation

•  Eddy Current Applications: discontinuity detection; IACS resistivity; automation; methods; physical properties; standards

•  Specialized NDT Methods I: sonics; infrared/thermal; acoustic emission

•  Specialized NDT Methods II: microwave; optical holography; acoustic holography; less common methods

•  Interpretation & Classification of Indications: types of indications; types of discontinuities; interpretation

•  Nondestructive Testing Standards and Specifications

WHO SHOULD ENROLL:

•  Technicians.

•  Engineers

•  Managers

•  Anyone who wants an introduction to the fundamentals of NDT

•  Seasoned personnel make decisions in en­vironmental, economic and quality control

Applied Techniques for Failure Analysis

COURSE OUTLINE

•  Discussion of the mechanisms of failure of ductile and brittle materials

•  Discussion of the mechanism of failure of specific engineering components

•  Emphasis on objective failure analysis using the physical evidence

•  Discussions on collection of the physical evidence

•  Discussions on the use of information not provided in physical evidence

•  Instruction in identifying, and preserving evidence

•  Instruction on preparing failure samples for metallographic examination without destroying the failure evidence

•  Photography of failure analysis specimens and metallographic mounts

•  Instruction on the use of optical equipment, metallurgical microscopes, metallographs, and SEM

•  Use of hardness testing methods to establish processing history of samples

•  Laboratory techniques to recreate failures (impact or tensile tests, corrosion tests)

WHO SHOULD ENROLL:

•  Engineers

•  Metallographers

•  Technicians

•  Quality Control Personnel

•  Design and Process Engineers

 

SUGGESTED PRE_EQUISITES:

•  Practical Interpretation of Microstructures

•  Microstructural Analysis of Ferrous Alloys

•  Metallographic Interpretation,

 

Practical Fracture Mechanics & Fractography

COURSE OUTLINE

•  Linear elastic FM concepts

•  Crack tip plasticity and R curves

•  Fracture toughness testing - K le and K-R curves Fatigue - conventional, crack growth rate, threshold fatigue

•  Stress corrosion cracking - monotonic and cyclic

•  Applications - life prediction, leak before break, proof testing

•  Nonlinear FM concepts - J integral, COD, handbook calculations

•  Ductile fracture testing - J le J-R curves, CTOD testing, common standards

•  Applications - Failure assessment diagrams, design curves, fracture control plans

•  Creep cracking

•  Problem solving workshop

•  Transition temperature approaches to fracture toughness

•  Materials variables affecting toughness ­- composition, microstructure, anisotropy

•  Macro and microfractography laboratory

•  115. Quantitative macrofractography using Kle

•  Quantitative microfractography - striation analysis in cyclic loading

 

COURSE OVERVIEW:

This course is designed to cover two specific areas: fracture mechanics and materials issues, fractography and quantitative fractography. Topics covered include: design and failure analysis for monotonic and cyclic loaded components, practical application of the stress intensity factor and the integral for monotonic and cyclic loading, materials data trends, laboratory macro- and micro-examination of failed parts, and qualitative and quantitative macro- and micro-fractography.

 

WHO SHOULD ENROLL:

This course is designed for engineers who need to be able to use fracture mechanics in a practical way, in both design and in failure analysis. Participants should have a degree in engineering, including introductory courses in mechanics and materials, but no prior knowledge of either fracture mechanics or materials issues is presumed. Participants will have, upon completion of the course, the necessary background to perform analytical analyzes for prevention of failure in flawed materials.

Practical Fracture Analysis

 

COURSE OUTLINE

•  Understanding Levels of Causes of Failures: Physical (improper heat treatment, for example) and mental/ psychological (lack of training, for example) and time of origin of causes (design phase, manufacturing, maintenance, use, complex interactions)

•  Getting Set up to do a Failure Investigation: Understanding human nature-What physical actions are required (and why) in a failure analysis: First do nothing, then tune your mind so that you can properly preserve evidence; collect information; decide which analytical tests to run. Hints and techniques for evidence preservation in the lab and in the field. Basic visual examination and macrophotography

•  Practical Fractography: Interpreting visible (macro- and microscale) characteristics on broken objects to obtain information about the stresses that caused the crack and the condition of the component

•  Crash course in principles of materials science and engineering : Atoms, crystals, grains, anisotropy, the process, structure, properties triangle, review of phase diagrams, CCC curves and jominy data for steels

•  Visual examination and macro- and micro­fractography: Witness marks, distinguishing monotonic ("static") from cyclic loading, finding the crack initiation(s), "non-fracture" features

•  Use of hardness tests in fracture analysis

•  The relationship between stress state, material behavior, and fracture features: States of stress in axial, bending, torsion and direct shear loading in cylindrical, prismatic, plate, and pressure vessel geometries for ductile and brittle materials. Orientation and characterization of fracture surfaces and states of and levels of stress. Expected crack features

•  Macrofractography: Interpreting actual macro fractographic features and non-fracture features. Identification of crack initiation site(s) and crack propagation direction. Differences in appearance for monotonic vs. cyclic loading. Appearance of axial, bending and torsion loading conditions

•  Typical imperfections (metallurgical and geometric) and their location encountered in fabricated components, and deliberate and inadvertently surface treated components

•  Microfractography: Detecting presence/absence of fatigue striations; classic microscale ductile and brittle fracture appearance; causes for, and appearance of, intergranular fracture

•  Case histories to illustrate how the component pieces of the analysis are put together.

•  Evaluation of Failure Investigation Data and Reports: Interpretation of data from visual inspection, fractography, mechanical, metallographic and chemical testing (comparison to specifications and reasonable expectations-or "Why you need a materials expert"); where to take test specimens, looking for anomalies; self consistency in conclusions of the various tests. Comments on failure analysis during the prototype testing phase.

 

COURSE OVERVIEW:

 

•  To help design, quality, manufacturing engineers, and their managers understand what types of benefits they can get from a properly performed fracture analysis.

•  To help more experienced fracture analysis practitioners improve their ability to interpret and communicate the data provided by the tests typically performed during a failure analysis.

•  Learn techniques which are most useful for structural and machine components subject to failure by fracture. (Wear will not specifically be covered.) The techniques presented are useful for a very broad range of materials. However, most of the examples will be metallic, with a few Polymeric.

 

The course will include student participation and demonstrations including macrophotography, macro- and microhardness testing, specimen cleaning, macro- and microfracture examination (SEM), EDS chemical analysis in the SEM, as well as metallographic specimen preparation and examination. If time permits, we may be able to com­ment on parts that you bring along.

 

SUGGESTED PREREQUISITES:

This class is not geared to entry-level technicians or engineers. An engineering degree and some experience is desirable; successful completion of an ASM Education class in Failure Analysis and some on-the-job experience is an adequate substitution.

 

Mechanical Testing of Metals

 

COURSE OUTLINE

1. Introduction to Mechanical Testing: mechanical tests to predict suitability for service and suitability for manufacture; statistical variation of mechanical properties; documentation of test data
2. Instrumentation and Calibration of Mechanical Testing Equipment: calibration of load frames, extensometers, hardness testers; specification and certification of calibration
3. Hardness Testing: static indentation tests; rebound tests; macro and micro scale testing; Brinell, Rockwell, Knoop, Vickers and Scleroscope tests; correlation of hardness with other mechanical and physical properties
4. Fundamentals of Tension and Compression Testing: elastic and plastic behavior, nominal and true stress; nominal and true (logarithmic) strain; strain rate; definitions of standard mechanical properties; effects of loading rate and specimen geometry on test results; standardized testing procedures; material and microstructural variables
5. Special Applications of Tension and Compression Testing: micro and macro scale yield stress determination; the Bauschinger effect; accurate modulus determination; testing of components (threaded fasteners, chain, wire rope)
6. Shear, Torsion, Creep and Creep Rupture Testing: determination of stresses in shear and creep testing; material behavior at elevated temperature (elastic modulus, thermal expansion, creep and stress relaxation); stress rupture testing and stress-rupture parameters (Larson-Miller, Sherby-Dorn)
7. Ductility and Formability Testing: bulk material forming (compression, open and closed die forging); sheet stretching and drawing; strain and strain rate hardening; onset of instability; anisotropy; determin­ation of r-values, and strain hardening exponents
8. Fracture Testing: ductile vs. brittle behavior, pendulum impact (transition temperature) testing; drop weight testing; notched tensile testing, fracture mechanics testing; composition and microstructure variables
9. Fatigue Testing: stress based, strain based, and fracture mechanics based testing; calculation of bending stresses; effects due to geometric variables; 'effects due to metallurgical variables

 

SUGGESTED PREREQUISITES:

• Some exposure to microstructural examination and the correlation of microstructure with mechanical properties
• Mathematics background that includes algebra and the use of logarithms

 

How to Organize and Run a Failure Investigation

 

COURSE OUTLINE

1. What is a Failure? The six reasons failures happen. The various failure mechanisms
2. What is a Failure Investigation? Why is it important? What are the benefits of a failure investigation? Why find the root cause?
3. How to Organize a Failure Investigation: Problem solving; Organizing the approach; Setting goals and objectives; Understanding constraints and limitations; Working in parallel or in series; Gathering information &: becoming the expert; How to protect and document the failure scene and/or hardware; Fault tree analysis; Failure mode assessment; Creation of a technical plan; Support tests that can eliminate causes and questions; Logic and deductive reasoning; Documenting the work; Recommendations and corrective actions; Failure investigation pitfalls

 

WHO SHOULD ENROLL:

This course is primarily intended for people who are new to failure investigation or for those who want an, update. It is also beneficial for technicians or managers who are interested in understanding how a failure analysis is organized and how it can be beneficial to Total Quality Management or Continuous Improvement. Discover how the results of the failure investigation can provide essential and interactive feedback to the design and manufacturing departments.

Principles of Failure Analysis

 

COURSE OUTLINE:

•  General Procedures for Failure Analysis: collection of data and samples; preliminary examination; nondestructive inspection; mechanical testing; selection and preservation of fracture surfaces; macroscopic and rnicroscopic exami­nation; selection; preparation and examination of metallo­graphic sections; fracture classification; report writing

•  Types of Failure and Stress: fracture, wear, corrosion, and distortion failures; tensile, compressive, torsional and shear stresses; residual stress

•  Ductile and Brittle Fractures: definitions and comparisons; dimple rupture; tearing and shearing;

1. plastic deformation ductile-brittle transition; cleavage; intergranular fracture; thermally-induced and environmentally-assisted embrittlement; effect of fabrication and heat treatment; residual stress

•  Fatigue Failures: factors affecting fatigue life; stages of fatigue fracture; fatigue cracking; effects of variables; mean stress; stress concentration; metal characteristics; manufac­turing process; elevated temperatures; contact fatigue

•  Wear Failures: abrasive wear; adhesive wear; role of friction; lubricated wear; lubricant failures; nonlubricated wear; examination of worn parts; effect of microstructure and hardness; surface-fatigue pitting; wear rates

•  Corrosion Failures: electrochemical reactions; types of corrosion; velocity-affected corrosion; bacterial and bio-fouling corrosion; underground corrosion; atmospheric corrosion; corrective and preventative measures; stress corrosion cracking; analysis of failure

•  Elevated-Temperature Failures: creep; stress rupture; thermal fatigue; effect of atmospheric environment; failures in industrial application; testing techniques

•  Failures of Cast and Wrought Ferrous Metals: casting defects categories; microstructural and compositional effects; residual stress; corrosion; metal behavior during hot working; ingot imperfections; material selection; materials imperfections

•  Failures of Welded, Brazed and Soldered joints: dis­continuities in arc welds; low-carbon steels; high-carbon steels; alloy steels; stainless steels; heat-resisting alloys; aluminum alloys; titanium alloys; electroslag welds; resistance welds; flash and upset-welds; friction welds; electron beam welds; brazed and soldered joints

•  Failures of Tools and Dies: influence of design; effect of heat treatment; post heat treatment; machining damage; hot work dies; mill rolls; weld repair

•  Failures of Shafts and Bearings: fracture origins in shafts; fatigue and wear failures of shafts; ductile and brittle failures in shafts; shaft stress-raisers; failure mechanisms of slide bearings; effect of foreign particles, lubrication, operating temperatures, overloading and improper assembly on slide bearing failures; failures of rolling element bearings; roller bearing failures caused by fatigue, wear, fretting, corrosion and plastic flow; roller bearing practices related to fabrication, heat treatment and lubrication

•  Failure of Gears: gear-tooth contact as it relates to wear pattern and tooth ratio; operating loads; causes of gear failure; classification of gear failures' to include wear, surface fatigue, plastic flow and fracture; failures due to processing; design related cracking; fracture due to heavy loading and wear

•  Failures of Mechanical Fasteners: threaded fasteners: failure origins, causes of failures, fretting failures, corrosion, hydrogen damage, damage due to elevated temperatures; rivets: shear in shank failures, bearing surface failures, stress corrosion cracking; blind fasteners: types and causes of failures

•  Failures of Boilers and Heat Exchangers: failure of boilers and related equipment: rupture from over­heating, rupture from embrittlement, corrosion and scaling, fatigue and erosion, stress corrosion cracking, multiple mode failures; failure of heat exchangers: operating conditions, sources of failures, corrosion, stress corrosion cracking, corrosion fatigue, weld joints, effect of elevated temperatures, failure analysis procedures

•  Failures of Pressure Vessels: causes of failures and procedures for analysis; metallurgical discontinuities; fabrication practices; pressure vessels constructed of composite materials; service-related failures; brittle and ductile fractures; creep and stress rupture

 

WHO SHOULD ENROLL:

• People new to failure analysis or those who want an update
• Technicians
• Those interested in understanding how knowledge of failure analysis can lead to better productivity

 

SUGGESTED PREREQUISITES:

• Metallurgy for the Non-Metallurgist
• How to Organize and Run a Failure Investigation
• Elements of Metallurgy ­
• Metallographic Interpretation
• Mechanical testing knowledge is helpful