HTU Engineering Science: Characteristics and Properties of Materials

This assignment delves into the properties of engineering materials and various testing methods, distinguishing between destructive and non-destructive approaches. Destructive methods, such as bend, break, tensile, hardness, and impact tests, involve material breakdown to examine properties like toughness and strength. Non-destructive methods, including magnetic particle, liquid penetrant, ultrasonic, and radiographic testing, preserve the material's structure. The assignment also discusses material selection for turbine blades, highlighting titanium alloys for their weight, temperature resistance, and corrosion resistance. Furthermore, it addresses common issues in airframes detectable through NDTs and lists fifteen NDTs used by a Jordanian company, alongside other companies utilizing NDTs. The document concludes with destructive methods like tensile and bend tests. The Rockwell test is mentioned as a method to determine material effectiveness. This comprehensive analysis provides a thorough understanding of material properties and testing methodologies.

ENGINEERING MATHEMATICS
[Author Name(s), First M. Last, Omit Titles and Degrees]
[Institutional Affiliation(s)]

Destructive Test methods
The destructive test methods include those practices where the material is broken down so
that its properties such as toughness, strength and hardness can be examined. A typical
example may include finding if the quality of the weld is just perfect enough to sustain a
particular pressure.
The destructive tests include the following;
 Bend test
 Break tests
 Tensile tests
 Hardness tests
 Impact tests
 Bent tests
This type of test usually involves breaking of the material at the midpoint thereby causing a
concave surface Blitz (2012). These operations are performed to determine the resistance to
fracture by the material or to determine the ductility of the material. The main aim of this
particular is not to load the material up to the point it fails but rather to deform the sample in
the specific shape.

The break tests
This kind of test is used to evaluate the quality of the weld. The specimen is usually made out
of the material for the weld. The stress concentrators are made in the form of the specimen.
The material under test is broken and the surface observed.
Tensile testing methods
In this type of testing, the material sample is subjected to a controlled tensional force until it
reaches failure. The material properties such as ultimate strengths and the breaking strengths
can be determined.

Hardness tests
This is a method that is employed to determine the hardness of the material. The hardness of
the material is its resistance to permanent defamation.
Question 2
 The material used for the making of the turbine blade must be able to meet the
following characteristics.
 It must withstand the hot corrosion and the effects of the erosion of the gases that are
flowing Xu et al. (2013).
 The material must withstand the static and the constantly alternating forces or the
stresses that are continuously applied to the parts.
 The material must show the good durability and stability and should not be easily
destroyed with the substrate that is present.
 The mechanical properties required should be met.
The alloy of the aluminium and the steel which is the titanium is normally preferred. The
material-titanium is preferred because of the following reasons.

Titanium has relatively reduced weight as opposed to the steel and the nickel whose alloys
are known to be heavy.
The level of temperatures is normally high but this particular metal can withstand it
The metal has relatively proper resistance to corrosion besides the perfect galvanic
compatibility with the polymer matrix of the various composites Hoła et al. (2010).
In order to determine the effectiveness of the material chosen, the Rockwell test was used.
The test involves pressing a diamond cone into the material. Normally the cone is at 120
degrees of the angle. When the cone is not available then the steel ball may be used instead.
The extent of hardness of the material is that level of plastic deformation that is obtained. The
Rockwell hardness tester is therefore used.
This particular method of hardness tests is preferred because of the following reasons.
The process is so simple to follow, it is very quick to do and it is suitable for checking the
product of the large size.
Question 3
The differences between the destructive and the non-destructive tests

Nearly all the destructive tests involve the breaking of the sample material under the test. The
load testing to failure is a typical example in this particular method. The tests that are usually
done to the hard materials are also considered destructive though the material is never
damaged García-Martín et al. (2011).
The non-destructive methods never alter the structure of the sample that is under test. The use
of the Ultrasound technique is a typical example here. Although the rebound hammers testing
usually leaves some small indentation in the surface of the lower concrete. The indentation is
never used to indicate the strength instead it is a reflection of the energy impact
Question 4
The non-destructive tests method
Magnetic particle testing
It uses one or several magnetic fields to locate the surface or near surface discontinuities.
This can be achieved using either permanent magnet or electromagnet. When the magnetic
field comes across the discontinuity, it wills transverse to the direction of the fields

Liquid penetrant testing
It involves application of a low viscous fluid on the material surface. The liquid will penetrate
into the voids and the fissures. The excess liquid is removed and the sample analysed.
Ultrasonic testing
It involves introducing a very high frequency sound into the part that is being investigated.
The sound that is reflected back when the sound hit a material with different acoustic quality
is then analysed Adzhubei et al. (2010).
Radiographic testing
The sample under test is subjected to the penetrating radiation. The non-uniform penetration
in some parts could indicate the presence of defects.

Question 5
The common issues in the airframes that utilises the NDTs
 The parts of the plane are usually subjected to loading and unloading. The fatigue
cracks are developed that are usually detected using the NDTs.
 The parts of the plane are sometimes under the attack of the corrosion from the
condensed mist Sunyaev, S. R. (2010)
 The common methods used here include the eddy current and the ultrasonic
inspection methods.
 The techniques are used to measure the thickness of the aircraft parts

Question 6
The fifteen NDTs used by the Jordanian company
 Laser testing
 Dye penetrant inspection-the dye is spread on the surface and the level of penetration
checked
 Electromagnetic testing-spreading of the magnetic iron filling and studying a
particular pattern
 Acoustic mission-uses sound waves for the detection.
 Leak testing-it is used to detect cracks on the surfaces using low viscous liquids.
 Magnetic resonance imaging-Used in the determination of the quality of the images
produced by the magnetic fields Paech & Tracey (2013)
 Spectroscopy-The crystal structure of the components are studied using this method.
 Optical microscopy-light rays are used to detect for the optical properties of the
material opaque or transparent
 Positive material identification-Perfect for the hardness determination
 Radiographic testing-The material is subjected to intense radio waves and their crystal
structure studied.
 Metallographic replicas-used in the study of the metal structures in terms of the
particle arrangement
 Ultrasonic testing-The waves of relatively short wavelengths and high speeds are used
in the analysis of the material property
 Resonant inspection-It is also used in the determination of the uniformity of the
particle distribution in the material.
 Surface temper etch-It is for the checking of the misalignment on the surfaces.
 Scanning electron microscopy-The perfect surface finish is detected using the method

 Thickness measurement-used for checking the precious thickness parts e.g. blade
thickness.
The destructive methods used include the following
 Tensile test-The material is subjected to the tensional forces in the view to obtain the
tensile strength of the material.
 Bend test-The material under test is introduced on the bending machine to determine
the possible formation of the fractures during the bending exercise Zoughi (2012)
Question 7
Other companies using the NDTs include the following
I. The Gulf Engineering Testing
II. The National Inspection and Technician Services.
III. New Engineering Vision for Contracting, NDT and Engineering.
IV. Jordan Aeronautical Systems

References
Blitz, J. (2012). Electrical and magnetic methods of non-destructive testing (Vol. 3). Springer
Science & Business Media
Adzhubei, I. A., Schmidt, S., Peshkin, L., Ramensky, V. E., Gerasimova, A., Bork, P., ... &
Sunyaev, S. R. (2010). A method and server for predicting damaging missense
mutations. Nature methods, 7(4), 248
Zoughi, R. (2012). Microwave non-destructive testing and evaluation principles (Vol. 4).
Springer Science & Business Media.
García-Martín, J., Gómez-Gil, J., & Vázquez-Sánchez, E. (2011). Non-destructive techniques
based on eddy current testing. Sensors, 11(3), 2525-2565
Hoła, J., & Schabowicz, K. (2010). State-of-the-art non-destructive methods for diagnostic
testing of building structures–anticipated development trends. Archives of civil and
mechanical engineering, 10(3), 5-18
Paech, K., & Tracey, M. V. (2013). Modern Methods of Plant Analysis/Moderne Methoden
der Pflanzenanalyse (Vol. 2). Springer Science & Business Media.

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