Sunday, 12 January 2020 08:27

Department Oral Defense of Thesis/Dissertation

A master’s student “Harir Salman Muhammad” defended her thesis entitled “Effect of Cryogenic Heat Treatment on Mechanical and Microstructural Properties of Welded Martensitic Stainless Steel” on Monday, December, 1st, at the conference room C/ Materials Engineering Department/University of Technology. The Committee included:

  1. Assistant Professor Fadil Abbas Hashim / University of Technology/ Materials Engineering Department as a chair.
  2. Assistant Professor Ayad Murad Takhakh/ Alnahrayn University/ Mechanical Engineering Department as a committee member.
  3. Dr. Arwa Faraj Tawfiq/ University of Technology/ Materials Engineering Department as a committee member.
  4. Professor Ali Husayn Otaiwi/ University of Technology/ Materials Engineering Department as an adviser.
  5. Assistant Professor Jamal Jalal Dawood/ University of Technology/ Materials Engineering Department as an adviser.

 

Abstract

       Martensitic stainless steels (MSS) are vastly used in industries because of their properties that mix good mechanical and corrosion resistance in addition to their ability to be heat treated to different strength stages. Moreover, these steels are generally used for various range of applications like nuclear power plants, steam generators, turbine, mixer blades and surgical tools. These applications are subjected through operation to different environment, so they need a frequent maintenance and it is necessary to enhance their properties by choosing an appropriate heat treatment and welding type.

       AISI 420 is one of these steels used extensively in this class for parts requiring a combination of high tensile strength, good toughness and corrosion resistance. Furthermore, heat treatment was  recommended as one of the best ways that improve these properties. Hence, the effects of astenitizing temperature, time, and tempering temperature will change the microstructure and mechanical properties of material.

       By applying suitable heat treatment procedures, the properties of martensitic stainless steels are greatly modified.  Poor weldability and cold cracking sensitivity are seen to be the foremost difficulties that are challenged in joining these steels. Cryogenic and heat treatments (CT and HT) are considered one of  the ways that used to enhance the mechanical properties of these steels, enhance the dimensional stability by means of transformation, in addition to  minimizing the retained austenite,  deformation concerning  the martensite then carbide refinement.    In current research, the weldability of AISI 420 MSS by tungsten arc welding (TIG) method has been explored. The weld joints were prepared by joining AISI 420 MSS with square butt joint. Basically, welding procedures were developed by using two types of austenitic fillers:  ER 309L and ER 310L.  Effects of  post weld heat treatments (PWHT) on mechanical and microstructure properties of  welded AISI 420 MSS have also been determined. PWHT involved conventional heat treatments like annealing , hardening and tempering at 200°C  ,500°C for duration time of about  15 min and  cryogenic treatments .Optical microscope, SEM analysis, EDS analysis, XRD, micro-hardness and tensile test were conducted in state of base metal and after PWHT.   Experimental result showed an increase in tensile strength of samples that were treated cryogenically and tempered at 500°C. To give more illustration the maximum hardness was (414 HV) in conventional heat treated samples that tempered at 200°C , precipitation of small carbides were observed that this is responsible for the improvement in the mechanical properties of the material. Hardness at the HAZ region in state of DCT in all weldments was reduced as compared to hardness of HAZ region of CHT.  The best filler used by TIG welding was ER 309L, where it gives the best results. Assistant Professor Basim Ajeel Abbas/ University of Babylon / Mechanical Engineering Department reviewed and characterized the thesis by the methods of science, whereas Assistant Professor Mayada Raheem Isa/ University of Technology/ English Language Center reviewed the thesis linguistically to meet the style of English. Congratulations to the student on her graduation.

A doctoral student “Ahmad Saad Kadhim” defened his dissertation entitled “Properties of Self Compacting Cementitious Composite Containing Nano Sustainable Materials” on Thursday, December, 5th, at the conference room C/ Materials Engineering Department/University of Technology. The Committee included:

  1. Professor Ahmed Muhammad Hasan Algaban/ University of Technology/ Materials Engineering Department as a chair.
  2. Professor Saad Badri Hasson Farid/ University of Technology/ Materials Engineering Department as a committee member.
  3. Assistant Professor Maan Salman Hasan/ University of Technology/ Civil Engineering Department as a committee member.
  4. Assistant Professor Zina Khudayer Abbas/ University of Baghdad/ Civil Engineering Department as a committee member.
  5. Assistant Professor Basma Muhammad Fahad/ Mustansiriyah University / Materials Engineering Department as a committee member.
  6. Professor Alaa Abdulhasan Ateya/ University of Technology/ Materials Engineering Department as an adviser
  7. Professor Shakir Ahmed Salih/ University of Technology/ Materials Engineering Department as an adviser

 

Abstract

Self-compacting mortars considered as new technology products especially preferred to use for the rehabilitation and repair of the reinforced concrete structure. In recent years, there has been increasing demand to recycle wastes materials produced by industrial processing in order to reduce environmental problems and promote sustainable development. The nanoparticles, both as filler or binder, could be enhanced the performance of the interfacial transition zone between the cement matrix and the aggregate as well as increases the overall quality of the cement matrix itself. The introduction of nanoparticles allows for the creation of the same identical product with a better microstructure and without causing the changes in the chemical composition of the products itself. Nano blast furnace slag and nano cement kiln dust were prepared and used as additives to the self-compacting mortar in (1, 2, 3, 4 and 5 %) by weight of cement to be used as cementitious sustainable materials.

The aim of this thesis was to investigate the influence of Nano sustainable materials such as blast furnace slag and cement kiln dust which are used as additives by weight of cementitious materials on the fresh and hardened properties of self-compacting mortar. Nanoparticle size was provided and checked by Laser Particle Size Analysis, Atomic Force Microscopy and Field Emission Scanning Electron Microscopy. Flowability of self-compacting mortar can be determined by using the mini flow table and mini v-funnel tests. Experiments were performed to assess the physical and mechanical properties of self-compacting mortar such as (compressive strength, direct tensile strength, flexural strength, dry density, water absorption, total porosity, dry free shrinkage) and microstructural homogeneity  (FESEM). In addition, the corrosion rate was also conducted at 30 and 180 days age. Mechanical and physical properties of mortar were carried out at 7, 28 and 90 days age. The experimental results of hardened mortar showed that the modification and enhancement of the compressive, direct tensile and flexural strengths were increased as nanoparticles powder percentage increases and modified with curing age. Also; the dry free shrinkage, water absorption, and porosity were decreased as a Nanopowder percentage increased. While the density of self-compacting mortar was increased as Nanopowder percentage increased. The microstructure homogeneity and nanoparticles distributions of self-compacting mortar have explained the enhancement and the performance of interfacial transition zone between the aggregates and cementitious materials matrix as well as increase the quality of the cement matrix itself. In addition, the results indicated that the corrosion rate of reinforced mortar decreased as nanoparticles additives increased and with curing time. Furthermore, the using of corrosion inhibitors powders were enhanced reinforced mortar properties against corrosion.

 Professor Shakir Jahil Edrees/ University of Babylon / Materials Engineering Department reviewed and characterized the dissertation by the methods of science, whereas Dr. Qusay Fadil Hasan/ University of Technology/ Control and Systems Engineering Department reviewed the dissertation linguistically to meet the style of English. Congratulations to the student on his graduation.

A master’s student “Iva Adel Yaqo” defended her thesis entitled “Industrial Application of Some Prepared Heterocyclic Derivatives as Corrosion Inhibitor” on Wednesday, December, 11th, at the conference room C/ Materials Engineering Department/University of Technology. The Committee included:

  1. Professor Anees Abdulaah Kadhim / University of Diyala/ Chemical Engineering Department as a chair.
  2. Assistant Professor Niveen Jamal Abdulqader/ University of Technology/ Materials Engineering Department as a committee member.
  3. Dr. Raad Suhail Ahmad/ University of Technology/ Materials Engineering Department as a committee member.
  4. Professor Rana Afif Majeed/ University of Technology/ Materials Engineering Department as an adviser.
  5. Assistant Professor Majid Hameed Abdulmajeed/ University of Technology/ Materials Engineering Department as an adviser.

 

Abstract

       In this study, the investigation on the efficiency of three organic derivatives (3,5-di(4-hydroxyphenyl)-4-amino-1,2,4-triazole (HAT), 4-[3-(4-methylphenyl)-1,2,4-oxadiazol-5-yl]-phenol (MOP), 4-(5-(p-tolyl)-1,3,4-thiadiazol-2-yl)phenol (TTP) were done as an anti-corrosion materials for carbon steel (type 285Gr C) by electrochemical method at (303, 313, 323, and 333 K) and (100, 200, 300, 400 and 500 ppm) in kerosene medium.

   The results have shown that compounds gave good efficiencies at experimental conditions. The highest performance of inhibition efficiency (IE%) was 86.74% which obtained in 100 ppm and 333 K for HAT and 88.95% in 500 ppm of inhibitor at 303 K for MOP, while TTP has the maximum inhibition efficiency equal to 87.18% in 400 ppm at 333 K.

   Generally, the polarization behavior revealed that these inhibitors act as mixed-type inhibitors; also, the corrosion inhibition data were measured and discussed depending on Tafel curves.

   The microstructure of the uninhibited and inhibited alloy surfaces was analyzed to show the chemical composition of the adsorbed film by scanning electron microscopes (SEM), with energy-dispersive X-ray spectroscopy (EDS). Atomic force microscopy (AFM) was used to confirm the presence of the inhibitor on the metallic surface. The Fourier transform infrared (FTIR) was revealed the bonding between the inhibitor and metal surface.

            The antimicrobial activity for HAT, MOP, and TTP was examined against some types of corrosive bacteria that can degrade hydrocarbons. Besides, the computational study (density functional theory; DFT) was calculated to show the active centers in the inhibitors and the correlation between molecular structure and inhibition efficiency. The thermodynamic parameters confirmed that the nature of adsorption is physically and it obeys Langmuir isotherm.

The dissertation was scientifically evaluated by Prof. Dr. Kholod Abd Saleh / Baghdad University / College of Science / Department of Chemistry Science, and linguistically by Assist. Prof. Dr. Mayada Rahim Esa / University of Technology / English Language Center.

The discussion of the dissertation was conducted in a scientific atmosphere and a master's degree with grade of pass was awarded to the student after the completion of all the corrections that have been decided by the examiners.

 

The Master student (Fatimah Alaa Adnan) discussed her dissertation entitled ( Fabrication and properties of zinc metal matrix composites reinforced with nanoparticles). The discussion was held on the discussions hall / building C / Department of Materials Engineering / University of Technology on Thursday (12/12/2019). The discussion committee was formed of the teaching staff listed:

 

Names

Place

Position in the Committee

Assist. Prof. Dr. Laith kais Abbas

University of Technology/ Department of Materials Engineering

Chief

Assist. Prof. Dr. Jamal Jalal Dawood

University of Technology/ Department of Materials Engineering

Member

Lec. Dr. Ahmed Mudafer Hashim

AL Qadisiya university/ Department of Materials Engineering

Member

Assist. Prof. Dr. Neveen Jamal Abdul-kader

University of Technology/ Department of Materials Engineering

Member-supervisor

Assist. Prof. Dr. Muhammed Salab Hamza

University of Technology/ Department of Materials Engineering

Member-supervisor

 

 The dissertation was scientifically evaluated by Prof. Dr. Ali H. Haleem / Babylon University / College of Engineering / Department of Materials Engineering, and linguistically by Assist. Prof. Dr. Mayada Rahim Esa / University of Technology / English Language Center.

The dissertation discussion was conducted in a scientific atmosphere and a master's degree with grade of pass was awarded to the student after the completion of all the corrections that have been decided by the examiners.

Read 35 times Last modified on Sunday, 12 January 2020 08:50

We have 36 guests and no members online

Top