Recent Question/Assignment

Course No: MEC3203 Course Name: MATERIALS TECHNOLOGY
Assessment No: 1 Internal
External This assignment carries 10% of the total assessment for this course (100 marks)
Examiner: MAINUL ISLAM Moderator: STEVEN GOH
Due Date: 19 April 2018
A coversheet with the relevant personal and course details is sufficient for electronic submissions.
There is no requirement to submit the official USQ coversheet. TopNZ students to use your own relevant coversheet. Please refer to the Marking Rubric when attempting the assignment.
TASKS: It is expected that you search, explore, identify, digest and evaluate relevant information resources (using the suggested SEDSA methodology or similar) on a subject/topic outlined in the case study for the course this semester.
Prepare a short literature review report (4-5 pages excluding the reference list and annotated bibliography) based on your evaluation of the relevant resources (an example is provided). As part of your research of literature, you will compile an annotated bibliography (template available on StudyDesk) prior to writing the literature review. The information resources expected in your reference list are:
• Textbooks and MEC3203 study materials
• Handbooks (at least 3; either hand-copy or online)
• Trade journals or magazines (identify and evaluate at least 3 references)
• Academic journals (identify and evaluate at least 10 references)
• Websites, Online videos or DVDs (identify and evaluate at least 10 references)
The evaluation should demonstrate a good level of critical thinking and a systematic evaluation of the literature. In-text citation and a reference list (based on Harvard style) are required.
TIP: It is recommended that you use some part of this assignment as a starting point to develop your literature review and preparatory work for Assignment 2 in the area of interest and in failure analysis and materials selection.
NOTE: It is advised that you keep a copy of your answers as it may be useful in completing your assignment 2, assist in your exam preparation, and during your professional life. You can find most of the information resources from your textbook, USQ Library Online, eBooks, Readings, and relevant library databases such as the “ASM Handbooks Online”. Use Harvard referencing style (refer to USQ Library website for details).
EXAMPLE – Literature Review
Mechanisms of Erosion-Corrosion & methods of prevention
Wear or the loss of material from the internal surfaces in specific regions of components exposed to the flow of fluids, with or without particles in suspension has been the cause of failure in many applications. In these failures there are a number of mechanisms that contribute to the deterioration of the components. These mechanisms have been monitored and documented both singularly and as a collective to better understand their contribution to the rate of deterioration. The literature reviewed considers the mechanisms of erosioncorrosion as well as the material selection.
Schweitzer (2010, p. 44) describes erosion as the deterioration due to a mechanical force and erosion corrosion as the accelerated rate of corrosion due to factors contributing to erosion. These factors include: Velocity, Turbulence, impingement, presence of suspended solids, angle of incidence, particle size, temperature and cavitation. Bayer (2004, p2) states, ‘wear is not a material property nor is it a unique physical mechanism. It is best thought of as a system response’, this tends to confirm the factors outlined by Schweitzer (2010).
Tang et al. (2009 p1), found the combination of electrochemical corrosion and mechanical wear to be the cause of material degradation in pipes. In their work, Tang et al. (2009 p1) noted that the fluid-structure interactions have a profound influence on the rate of erosioncorrosion. The shape of the passage influenced the local hydrodynamic conditions at the surface of the metal, in the worst cases, by introducing turbulence and high fluid shear stress increasing the mass transfer at the metal/electrolyte interface. Degradation in this case was related to the regions of turbulence and fluid shear stress removing the deposited corrosion products that were acting as protective films. This supports the point made by Bayer that wear is a system response and that one of the methods to reduce erosion-corrosion is to alter the geometry to minimise turbulence and high velocities. Fluids used by Tang et al. (2009) never contained noticeable particles in suspension, hence the erosion-corrosion was due to the corrosion and hydrodynamic mechanisms related to the passage geometry.
In cases where corrosion is the main mechanism for deterioration, corrosion inhibitors introduced to the fluid medium have been found to prevent general or uniform corrosion. However according to Schweitzer (2010, p. 326) corrosion inhibitors are limited in being able to prevent localised corrosion. Corrosion inhibitors form a protective film over the metal surface, and work by reducing either the anodic oxidation effect or the cathodic reduction effect, or both Schweitzer (2010, p. 309). Experimental tests carried out by Neville & Wang (2009, p203) agreed with Schweitzer (2010) that corrosion inhibitors contribute to reducing corrosion but also found that they reduced erosion-corrosion due to the smoothing effect the inhibitor had on the metals surface. It was found that the smoother surface reduced local turbulence and hence reduced erosion-corrosion, this correlates with the work done by Tang et al. (2009).
Corrosion can also be controlled by means of cathodic protection through the use of a sacrificial anode as shown by Hammond (2009). The Sydney opera house air conditioning cooling system is subjected to corrosive sea water. The piping systems are protected by sacrificial zinc blocks that are attached to the steel pipes so that an electro-chemical circuit is formed between them. Due to the zinc being less noble than the steel pipes, the zinc blocks are forced to act as the anode and corrode while protecting the steel piping that act as the cathode.
In addition to corrosion, solid particles in suspension of a flowing fluid accelerates wear through impingement, the impacts of the solid particles cause the surface of the metal to deform, fracture or displace completely as investigated by Rajaharm, Harvy & Wood (2009). In their finding they deduced that higher velocities and increased particle concentrations increased the wear rate, this is due to the increased number of impacts on the surface causing material loss and the higher velocity increasing the intensity of the impact. In cases where a passive metal is used, such as stainless steel, the corrosion element is reduced due to the formation of a self repairing protective film. However Hu & Neville (2003) also found that there was a relationship between the particle concentration and the rate at which the passive protecting film can reform. They found that there was a critical concentration of solid particles, above which the rate of erosion corrosion would accelerate due to corrosion as the film was no longer able to restore itself. The relationship of corrosion/wear and particle concentration is further complicated as found by Turrene, Fiset & Masounave (cited in Rajaharm, Harvy & Wood 2009, p. 250), that higher particle concentrations can also lead to a decrease in erosion rate, this is attributed to the particles rebounding off the surface and colliding with the stream particles close to the surface, thus deflecting them and protecting the surface.
Material selection importance was highlighted by work carried out by Tian, Addie & Visintainer (2009). They tested three grades of high-chrome cast irons, with increasing amounts of chrome content. As the chrome content increased so did the resistance to corrosive acidic conditions, but hardness dropped. The varying test conditions for the three materials included: Fluid pH 7 0 ppm cl-, pH 4 20k ppm cl-, pH 1.5 60k ppm cl-, particle sizes of 10µ, 148µ and 660µ. One would assume the more corrosive the fluid (lower pH with higher concentration cl) the better the performance of the cast iron with the higher chrome content. This was found to be true only for conditions where the highly acidic slurry contained particles in the 10µ size. As the particle size increased the harder, lower chrome containing cast iron showed better resistance to the overall corrosion erosion. Yaer et al. (2007) also found that the hardness of materials and the size of the particles are some of the dominant factors influencing erosion as did Balasubramanian et al. (2008). There is agreement with the point by Bayer (2004, p2) that wear is best thought of as a system response and not a material property, however there is some contradiction in the fact that a materials hardness is a material property. It is clear that material hardness does play a major role in erosion corrosion resistance, however due to the complexities of the system, it is important to understand the synergies between the effect of the corrosion component as well as the effect of the erosion component while selecting a material for use in the application. It is not as simple as merely selecting a harder, higher alloyed and more expensive material, as it has been found that in certain applications the seemingly ‘inferior’ material is better suited for the application.
Bayer, RG (2004) Engineering Design for Wear, 2nd edn, Marcel Dekker, New York.
Tang, P, Yang, J, Zheng, JY, Lam, CK, Wong, I & He, SZ (2009) Predicting Erosion-Corrosion Induced by the Interactions Between Multiphase Flow and Structure in Piping System, Journal of Pressure Vessel Technology, vol. 131, 061301, p.1-8
Schweitzer PA (2010) Fundamentals of corrosion, mechanisms, causes, and preventative methods, CRC Press, Boca Raton, Florida.
Erosion-corrosion (1995-2007) Corrosion testing laboratories Inc., Delaware, viewed 3 April 2010,
Corrosion of Metals and Their Alloys, Key to Metals, Switzerland, viewed 4 April 2010,
Baxter, R & Britton, J (2008) Offshore Cathodic Protection 101 What it is, and how it works,
Deepwater Corrosion Services inc., Houston, viewed 4 April 2010,
Cathodic Protection, Sasol, South Africa, viewed 4 April 2010,
Corrosion Failures (2007) Metallurgical Consultants, Florida, viewed 17 April 2010,
Tverberg, J (2008) ‘how to achieve corrosion resistance’, Plymouth Tube Co., Illinois, accessed 17 April 2010,
Hammond, R (2009) ‘Sydney opera house’, National Geographic channel, DSTV, South Africa, viewed 27 March 2010.
Corrosion Control, Corrosion Technology Laboratory, Florida, viewed 17 April 2010
Sacrificial Anodes for Cathodic Protection (2010) Deepwater Corrosion Services Inc., Houston, viewed 16 April 2010,
Prevention of velocity effects – erosion corrosion and cavitation, Canadian copper and brass development association, Canada, viewed 18 April 2010,
Tian, HH, Addie, GR & Visintainer, RJ (2009) ‘Erosion-corrosion performance of high-Cr cast iron alloys in flowing liquid – solid slurries’, Wear, vol. 267 (2009), p. 2039-2047.
Yaer, X, Shimizu, K, Matsumoto, H, Kitsudo, T & Momono, T (2007) Erosive wear characteristics of spheroidal carbides cast iron, Wear 264 (2008), p. 947-957.
Rajahram, SS, Harvey, TJ & Wood, RJK (2009) Erosion-corrosion resistance of engineering materials in various test conditions, Wear 267, p. 244-254.
Balasubramanian, V, Varahamoorthy, R, Ramachandran, CS & Babu, S (2008) Abrasive slurry wear behaviour of stainless steel surface produced by plasma transferred arc hardfacing process, Surface & Coatings Technology, 202, p. 3903-3912.
Neville, A & Wang, C (2009) Erosion-corrosion mitigation by corrosion inhibitors – An assessment of mechanisms, Wear 267, p. 195-203.
Turrene, S, Fiset, M & Masounave J (1989) The effect of sand concentration on the erosion of materials by a slurry jet, Wear 133, pp. 95-106 quoted in Rajahram, SS, Harvey, TJ & Wood, RJK (2009) Erosion-corrosion resistance of engineering materials in various test conditions, Wear 267, p. 244-254.
Hu, X & Neville, A (2003) The electrochemical response of stainless steels in liquid-solid impingement, Wear 258, pp. 641-648.
Askeland, DR & Phule, PP (2005) The science and engineering of materials, 5th edn, Thomson Learning, Australia, p. 821-826.
Meyers, JR (2005) Copper-Tube Corrosion in Domestic-Water Systems, Heating/Piping/Air Conditioning HPAC Engineering; Jun2005 Supplement, p22-31.
Jethra, R (2007) Steam Generation and Liquid Analysis, Power Engineering, November 2007, p. 152-160.
Gutzwiller, L (2008) No1 way to avoid catastrophic failure, Pollution Engineering July 2008, p.28-37.
Assessment criteria for MEC3203 Assignment 1 (100 marks)
Level 1 0-40 or poor attempt
at with no evaluation and synthesis of literature, or inadequate literature search Level 2 40-60 Adequate attempt at explaining the content but demonstrating limited evaluation and
synthesis of some
literature Level 3 60-80 Good attempt at demonstrating some evidence of evaluation and synthesis of most required literature Level 4 80-100
Excellent attempt at demonstrating evidence of evaluation and synthesis all required literature
No of