Manufacturing Engineering

Permanent URI for this collection

http://etd.aau.edu.et/handle/123456789/217

Browse

Browsing Manufacturing Engineering by Author "Henok Zewdu (Mr.)"

Now showing 1 - 4 of 4
  • No Thumbnail Available
    Item
    Analysis and Optimization of Process Parameters for Friction Stir Welding of Dissimilar Aluminum 6061 and Commercial Pure Titanium Metal
    (Addis Ababa University, 2024-06) Dawit Gebeyehu; Henok Zewdu (Mr.)
    Friction stir welding (FSW) is a solid-state weld process were invented in 1991 that broadly used by industries and preferred rather than other weld process due to its capability to weld similar and dissimilar materials under high quality. FSW offers a number of advantages over other weld methods, including being automatic, suitable for most materials, able to be performed in any position, having minimal distortion, and not requiring filler or shielding gas., can be employed under water, and environmentally friendly. In this research, a joint between 6061 aluminium alloy and commercially pure titanium Gr-1 was butt welded by using friction stir welding. at a speed of rotation (1100, 1400, 1600) rpm , a transfer (welding) speed at (50, 60, 80) mm×min-1, a tool pin profile (cylindrical, square, conical), and a dwell time of (5, 10, 15) sec. welded material microstructure and mechanical properties were assessed using the tensile test, the hardness test, and optical microscopy (OM), respectively. Tensile testing, hardness testing, and optical microscopy (OM) were used, respectively; to assess the mechanical characteristics and interfacial microstructure. The numbers of welding experiments were determined using both of the Taguchi and Grey relation analysis approaches. The strength of friction welded dissimilar joints and effect of parameters were analysed using ANOVA (analysis of variance) on Minitab 20 software. After the materials are welded successfully, their tensile strength and hardness were evaluated at room temperature. According to the results, the cylindrical pin profile, 1100-rpm rotational speed, 80 mm/min transverse speed and 15 sec dwell time are the optimal conditions for combining these different joints. In the stir zone, strengthening precipitates were distributed finely and uniformly.
  • No Thumbnail Available
    Item
    Development and Analysis of Composite Material using Honey comb Orientation of Bamboo Fiber and Epoxy Composite for Prosthetic Socket Application
    (Addis Ababa University, 2023-06) Yelshaday Regasa; Henok Zewdu (Mr.)
    This thesis focuses on utilizing honeycomb fiber orientation techniques to develop a prosthetic socket with enhanced mechanical properties at a lower cost. The current challenges in prosthesis production include the high cost of fibers and the inadequate strength of the composite fiber. To address these issues, this research explores the tensile characteristics, water absorption and impact strength of bamboo fiber reinforced epoxy composites with an optimized material mix ratio design. The Finite Element Method for Numerical Analysis is employed to predict the desired properties of the composite material. Using numerical analysis software solutions, the stacking sequence is determined based on established standards. The newly designed prosthetic socket is evaluated for improved qualities, such as stance stability, speed control, multiple speed adoption, shock absorption, and reduced weight throughout the entire cycle. By closely emulating nature, the study investigated the relationship between woven fiber orientations and honeycomb pattern fiber orientations. It examines the optimal material mix ratio design, as well as the best fiber orientation pattern and angle of fiber orientations. The obtained results include a tensile strength of 53.4 MPa, compressive strength of 57.6 MPa, flexural strength of 64.55 MPa, impact strength of 13.02 J/cm2, and water absorption rate of 2.31%. The findings of this research aim to contribute to the development of low-cost, high-strength composite materials for prosthetic sockets. Prosthetic socket designers can utilize these recommendations to improve the overall performance and durability of prostheses.
  • No Thumbnail Available
    Item
    Fabrication and Investigation of the effect of Machining Parameters on the Performance of Machining Al-TiB2 Composites
    (Addis Ababa University, 2023-01) Nobel Kassahun; Henok Zewdu (Mr.)
    Aluminum-based metal matrix composite materials are mostly used to design automobile parts and aircraft structures due to their lightweight and high strength. In this study, the stir casting method was used for the fabrication because it is the most effective method for manufacturing metal matrix composites due to its more effective and fairly uniform distribution. Machining of metal matrix composites was difficult in the turning process. This study investigates optimum cutting parameters for turning Al 6061- 10% TiB2 composite materials. The mechanical properties of Al-10% TiB2 composite were analyzed using the following tests: tensile test, hardness, and impact test. Al 6061- 10% TiB2 has a mechanical property i.e. tensile test the maximum result from the specimens was 242MPa but the average was (208MPa), hardness test by Rockwell hardness test the average result was (74.9HRH), and finally the Impact result was (311.67KJ/m2). The study considered the cutting parameters which are the cutting speed, depth of cut, and feed rate as input, surface roughness and material removal rate are the responses by using coated carbide tool on a CNC lathe machine. The effect of cutting parameters on Surface roughness and material removal rate were studied and analyzed. Experiments were conducted based on the Taguchi design of Experiments with orthogonal array L9, and the optimization of the results works with Analysis of Variance (ANOVA). The optimum responses of MRR and surface roughness were obtained at high cutting speed 1500rpm, high depth of cut 1.5mm, and medium feed rate 100mm/min.
  • No Thumbnail Available
    Item
    Optimization of process parameters in Friction Stir Welding of dissimilar aluminum alloys (AA6061–T6 and AA5052–H32)
    (Addis Ababa University, 2023-03) Wondu Tesfaye; Henok Zewdu (Mr.)
    Friction stir welding (FSW) is a solid-state welding method mostly used to join aluminum and aluminum alloys that has been used in aerospace, railway, automotive, and marine applications. This process is used for welding dissimilar aluminum alloys. Solid-state welding processes solve several problems that occur during fusion welding of Al-alloys like heat affected zone liquation cracking, porosity, and segregation. Aluminum Alloys of two different series AA5052 and AA6061 thickness of 6mm are Friction Stir welded using process parameters like tool rotational speed (900,1100,1400) rpm, transverse speed (40,50,60) mm/min, and pin profiles (cylindrical, conical, and square). This thesis aims to optimize the mechanical and metallurgical properties of the above dissimilar combination to evaluate the performance and characteristics of the welded joints. The combined Taguchi and Grey relation analysis experimental method was chosen to construct the number of welding experiments. Analysis of variance was performed to obtain the effect of the parameters on the Friction Stir welded joints strength. The plates are successfully welded, and the welded plates are tested at room temperature to examine their tensile strength and hardness. The findings indicate that the square pin profile, the rotational speed of 1400 rpm, and the transverse speed of 40 mm/min are the optimum parameters for joining these dissimilar joints. A fine and uniform distribution of strengthening precipitates was found in the stir zone.