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Material testing PDT 154/3
Week 1:
Introduction
Dr. Norshah Aizat Shuaib
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Agenda for today
u Introduc0on of the course (PDT 154/3)
u Introduc0on of material
u Why we need to study material
u Disaster related to material failure
u Innova9on in material
u Different material tests
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Teaching team
Dr. Norshah Aizat Shuaib
Miss Nurul Aida bin9 Mortar
Mr Nazmizan
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The Course – Material Tes0ng (PDT 154/3)
u In Malay: Pengujian Bahan
u Credit: 3
u Learning Approach
u Lecture: 2 hours per week, Tuesday @ 5.00 pm
u Laboratory: 3 hours per week, Thursday @ 8.00 am
u Assessment
u Examina9on (60%): Mid term 1 and 2 20%, Final 40%
u Coursework (40%): Lab report and exercise 20%, Oral/Viva/Quiz 5%, Laboratory test 15%, Assignment 5%
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Course outcome / objec0ve (CO): CO1:
Able to iden9fy the importance of materials tes9ng, the types of materials tes9ng, the basic of materials imperfec9on and impuri9es in solids
CO2:
Able to demonstrate the destruc9ve and non-‐destruc9ve materials tests using tes9ng machines.
CO3:
Able to analyze the result and defects that exist on inspec9on materials through destruc9ve and non-‐destruc9ve tes9ngs.
CO4:
Able to analyze physical and mechanical proper9es of materials through various tes9ng techniques such as compression test, charpy impact tes9ng, hardness test, magne9c par9cle test and liquid penetra9on test.
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Course content
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Course content
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Reading list
u Askeland, D. R., The Science and Engineering of Materials. 7th Ed. USA; Cengage Learning, 2016.
u Callister, W.D. Jr. Materials Science and Engineering: An Introduc9on. 5th Ed. New York: John Wiley, 2000.
You can find the books from the library.
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Why we need to study materials?
u As engineer or technologist, you will soon encounter design problem involving materials – so you need to understand materials that are available and how to test them.
u For example: In an automobile factory, piping line in oil refinery – which material to choose?
u One of the problems – to choose a material from thousand of materials
u There is a trade off when choosing materials – strength, duc9lity, temperature resistance, weight cost, etc.
u Material test is important.
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Material Science and Engineering
Credit diagram: Dr John Francis – University of Manchester
Material / product tests – we are here!
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Engineering disasters – why?
u Many engineering disasters can be due to a poor understanding of material behaviour, or a poor choice of material.
u Material tests will provide understanding on material proper9es and for monitoring purpose .
u For instance: u Tensile test will determine material ul9mate tensile strength and Young’s modulus
u Ultrasound test detects crack or void (for repair)
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Disaster 1: Space ShuXle Challenger (1986)
u On January 28, 1986, the American shujle orbiter Challenger broke up 73 seconds aker likoff,
u Claimed the lives of all seven astronauts aboard,
u Cause: two rubber O-‐rings, which had been designed to separate the sec9ons of the rocket booster, had failed due to cold temperatures on the morning of the launch.
u Unusually cold weather (-‐2°C), previous coldest launch (12°C)
Source: History.com
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Disaster 2: Liberty Ships
u Failure of World War II Liberty Ships
u Cause: Duc9le to brijle transi9on of metal due to low temperature
u Some of the ships went to North Atlan9c, the temperature went below transi9on temperature
(Reprinted with permission of Earl R. Parker, Brijle Behavior of Engineering Structures, Na9onal Academy of Sciences, Na9onal Research Council, John Wiley & Sons, New York, 1957 -‐ metallurgyandmaterials.wordpress.com
Source: UNSW
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Challenge in selec0on of material – material is keep on changing!
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Innova0on in materials What are differences in materials used in these products?
1. Boeing 707 and Airbus A350
2. Nokia 3310 and Iphone 7
3. Tennis/badminton racquet
(past and future)
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Innova0on in materials
Formula One car
Year 1960s: Aluminium frame, steel brakes, metal helmet, cojon clothing
Year 2000s: Composite (carbon) frame, composite (carbon) brake, composite (glass/carbon) helmet, aramid clothing
Usage of composite material is for the lightweight
Because materials keep changing, material tests need to be done frequently
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Material tests you will learn in this course:
u Tension and compression test
u Charpy impact test
u Fa9gue test
u Hardness test
u Ultrasonic test
u Eddy current test
u Magne9c par9cle and flow detector test
u Liquid penetra9on test
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Type of material tests
Destruc9ve
Non-‐destruc9ve
u Tensile test
u Compression test
u Charpy impact test
u Fa9gue test
u Hardness test
u Ultrasonic test
u Eddy current test
u Magne9c par9cle and flow detector test
u Liquid penetra9on test
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Destruc0ve test (DT):
u As the name suggests, destruc9ve tes9ng (DT) includes methods where your material is broken down in order to determine mechanical proper9es
u Carried out to the specimens failure, in order to understand a specimens performance or material behaviour under different loads.
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Tensile test
u Sample is subjected to control tension un9l failure
u Usually performed using a tensile machine, for instance Shimadzu Autograph AG-‐X
Shimadzu.com imrtest.com
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Compression test
u A compression test determines behavior of materials under crushing loads.
u The specimen is compressed and deforma9on at various loads is recorded.
ASM Handbook, Vol. 8, Mechanical Tes9ng and Evalua9on
admet.com Instron.com
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Charpy impact test u Impact test based on pendulum
u Tes9ng an object's ability to resist high-‐rate loading.
u An impact test is a test for determining the energy absorbed in fracturing a test piece at high velocity
Imrtest.com Instron.com
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Fa0gue test u Applying cyclic loading to sample to understand how it will perform under
similar condi9ons in actual use.
u The load applica9on can either be a repeated applica9on of a fixed load or simula9on of in-‐service loads.
u The load applica9on may be repeated millions of 9mes and up to several hundred 9mes per second
u For oscilla9ng or vibra9ng materials
u Paper clip experiment (Instron.com)
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Non Destruc0ve test (NDT):
Defini9on by (American Society of Non-‐destruc9ve Tes9ng):
The examina9on of an object with technology that does not affect the object’s future usefulness.
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Non Destruc0ve test (NDT): Manufacturers use NDT:
1. to ensure product integrity, and in turn, reliability
2. to avoid failures, prevent accidents and save human life
3. to make a profit
4. to ensure customer sa9sfac9on and maintain the manufacturer’s reputa9on
5. to aid in bejer product design
6. to control manufacturing processes
7. to lower manufacturing costs
8. to maintain uniform quality level
9. to ensure opera9onal readiness
Sarasini and Santulli (2012)
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Eddy current test
u Using alterna9ng electrical current to create alterna9ng magne9c field to detect defect, flaw and discon9nuity in product.
u Usually for conduc9ve material
(NDTA.org.nz)
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Liquid penetra0on test
u U9lises natural accumula9on of a fluid around a discon9nuity to recognise crack or surface defect
u Capillary ac9on ajracts the fluid to the con9nuity
u Visible light or UV light is used for inspec9on
(Image from Wikipedia)
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Ultrasonic test u Can be used for both metallic and
non metallic
u Use high frequency acous9c waves generated by piezoelectric transducers
u Acous9c waves propogate effec9vely through most structural materials, but dissipated or reflected by inhomogeni9es or discon9nui9es
u Ultrasonic test will provide informa9on such as thickness, size of discon9nuity etc. (Ni.com)
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Magne0c par0cle test
u For ferromagne9c materials (materials which can be easily magne9sed)
u Capable of detec9ng flaws open-‐to-‐surface and just below the surface
u Detec9on through interrup9on of flow of magne9c lines and magne9c par9cles
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DT VS NDT
Destruc0ve tests (DT) Non-‐destruc0ve tests (NDT)
Measurement are direct and reliable
Measurements indirect, needs to be verified
Tests made on sample, not objects
Test are made directly on objects
Prepara9on of the test specimen is costly
Very lijle prepara9on
Time consuming Test methods can be done rapidly / quickly
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Conclusions
At the comple9on of this course:
u You will have basic understanding on material tests
u You can differen9ate between DT and NDT
u You will be able to conduct several DTs and NDTs.
u You can also decide which material to use for your product
