scholarly journals Improving the surface properties of a Pelton turbine bucket via centrifugal casting technique

2017 ◽  
Vol 9 (10) ◽  
pp. 168781401772908
Author(s):  
Williams S Ebhota ◽  
Akhil S Karun ◽  
Freddie L Inambao
Keyword(s):  
Surface Properties ◽  
Centrifugal Casting ◽  
Casting Technique ◽  
Pelton Turbine ◽  
Turbine Bucket

Investigation of Functionally Graded Aluminium A356 Alloy and A356-10%SiCp Composite for Hydro Turbine Bucket Application

2016 ◽  
Vol 26 ◽  
pp. 30-46 ◽  
Author(s):  
Williams S. Ebhota ◽  
Akhil S. Karun ◽  
Freddie L. Inambao
Keyword(s):  
Heat Treatment ◽  
Tensile Stress ◽  
Centrifugal Casting ◽  
A356 Alloy ◽  
Casting Process ◽  
Ultimate Tensile Stress ◽  
Functionally Graded ◽  
Cnc Machining ◽  
Mould Material ◽  
Turbine Bucket

The study investigates the application of centrifugal casting process in the production of a complex shape component, Pelton turbine bucket. The bucket materials examined were functionally graded aluminium A356 alloy and A356-10%SiCp composite. A permanent mould for the casting of the bucket was designed with a Solidworks software and fabricated by the combination of CNC machining and welding. Oil hardening non-shrinking die steel (OHNS) was chosen for the mould material. The OHNS was heat treated and a hardness of 432 BHN was obtained. The mould was put into use, the buckets of A356 Alloy and A356-10%SiCp composite were cast, cut and machined into specimens. Some of the specimens were given T6 heat treatment and the specimens were prepared according to the designed investigations. The micrographs of A356-10%SiCp composite shows more concentration of SiCp particles at the inner periphery of the bucket. The maximum hardness of As-Cast A356 and A356-10%SiCp composite were 60 BRN and 95BRN respectively, recorded at the inner periphery of the bucket. And these values appreciated to 98BRN and 122BRN for A356 alloy and A356-10%SiCp composite respectively after heat treatment. The prediction curves of the ultimate tensile stress and yield tensile stress show the same trend as the hardness curves.

Spun Steel Pipes for the Offshore Industry

1983 ◽  
Vol 105 (1) ◽  
pp. 97-102 ◽  
Author(s):  
A. Royer ◽  
B. Dumas ◽  
M. Gantois
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Centrifugal Casting ◽  
High Strength ◽  
Controlled Rolling ◽  
Climatic Conditions ◽  
Casting Technique ◽  
Steel Pipes ◽  
Potential Applications ◽  
Offshore Industry

Many parts either for sea-line pipes as “buckle” or “crack arrestor,” or for structures may require the use of wall tubular products with high mechanical properties. Such heavy-wall pipes may be produced by centrifugal casting. Two Mn-Mo steels have been developed for medium-wall pipes (e≤35 mm) to be used under very severe climatic conditions: an acicular ferritic steel, a pearlite reduced steel produced by controlled rolling techniques [1, 2, 3]. More alloyed chemical composition and heat-treatments are needed to produce heavy-wall pipes. Then, production of such pipes is more difficult and sometimes impossible. Observations made on controlled-rolled Mn-Mo steel led to a better understanding of the influence of metallurgical structures and chemical composition on steel characteristics. Similar metallurgical structures can only be reached via other routes, for example centrifugal-casting of steel associated with heat-treatment, lead to the production of heavy-wall pipes with high strength and suitable transition temperature. After a brief description of the centrifugal casting technique, we introduce the grades developed for heavy-wall pipes with yield strength up to 100,000 psi. The mechanical properties, Battelle, fatigue, static bending, C.O.D., weldability, etc., of Centrishore II are given and compared to other materials. Possible offshore applications and other potential applications of parts produced by centrifugal casting are described.

Investigation of fatigue behavior of centrifuged series 3000 Al with addition of 26 wt% Cu

2020 ◽  
Vol 234 (10) ◽  
pp. 1375-1385
Author(s):  
Aref Mehditabar ◽  
Seyed E Vahdat ◽  
Gholam-Hossein Rahimi
Keyword(s):  
Electron Microscopy ◽  
Thermal Expansion ◽  
High Performance ◽  
Volume Fraction ◽  
Coefficient Of Thermal Expansion ◽  
Fatigue Behavior ◽  
Centrifugal Casting ◽  
Image Analyzer ◽  
Casting Technique ◽  
Wide Range

More than 70% of mechanical parts in a wide range of engineering fields fail by fatigue. In addition, centrifugal casting is identified as the most effective casting technique for production of high performance cylindrical parts. In this regard, the present work aims to investigate the fatigue behavior of series 3000 Al with addition of 26 wt% Cu produced through horizontal centrifugal casting method. Microstructure characterizations are precisely studied using scanning transmission electron microscopy and field emission scanning electron microscopy in conjunction with image analyzer software. Also, compressive behavior, hardness, coefficient of thermal expansion, and wear rate ( Wr) are measured applying Zwick Z100, Vickers hardness, DIL 805A/D, and pin-on-disc machines, respectively. The results indicate that the main intermetallic compound is Al2Cu-based particle, and a volume fraction of 31 vol.% is obtained. Besides, the compressive strength of 460 MPa, elastic modulus of 10.986 GPa, hardness of 152 HV, coefficient of thermal expansion of 1.7 × 10−5 1/°C, and wear resistance of 3.3 × 10−6 g/mm2 are measured. Finally, the four-point bending fatigue test is performed and the fatigue ratio of 0.109 at about 106 cycles to failure is obtained.

scholarly journals Flow in a Pelton Turbine Bucket: Numerical and Experimental Investigations

2005 ◽  
Vol 128 (2) ◽  
pp. 350-358 ◽  
Author(s):  
Alexandre Perrig ◽  
François Avellan ◽  
Jean-Louis Kueny ◽  
Mohamed Farhat ◽  
Etienne Parkinson
Keyword(s):  
Homogeneous Model ◽  
Free Surface Flow ◽  
Flow Patterns ◽  
Surface Flow ◽  
Experimental Investigations ◽  
Pressure Measurements ◽  
Two Phase ◽  
Pelton Turbine ◽  
Flow Visualizations ◽  
Turbine Bucket

The aim of the paper is to present the results of investigations conducted on the free surface flow in a Pelton turbine model bucket. Unsteady numerical simulations, based on the two-phase homogeneous model, are performed together with wall pressure measurements and flow visualizations. The results obtained allow defining five distinct zones in the bucket from the flow patterns and the pressure signal shapes. The results provided by the numerical simulation are compared for each zone. The flow patterns in the buckets are analyzed from the results. An investigation of the momentum transfer between the water particles and the bucket is performed, showing the regions of the bucket surface that contribute the most to the torque. The study is also conducted for the backside of the bucket, evidencing a probable Coanda interaction between the bucket cutout area and the water jet.

Investigation of Particle Segregation and Solidification Time in FGM's Using Centrifuge Casting Technique

2015 ◽  
Vol 766-767 ◽  
pp. 956-961
Author(s):  
K.S. Chethan ◽  
S. Kiran Aithal ◽  
A. Madhusudan ◽  
Rao Shailesh
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Particle Distribution ◽  
Centrifugal Casting ◽  
Casting Process ◽  
Functionally Graded ◽  
Particle Segregation ◽  
Graded Materials ◽  
Influence Of Process Parameters ◽  
Casting Technique

Functionally Graded Materials (FGM) is a newly evolved concept to get desired properties in the material wherein the intermediate layer is transient since the particle size distribution gradually changes. Centrifugal casting [1] can produce only hollow shapes and Centrifuge casting can produce solid shape FGM very effectively. The study of particle distribution in a fluid using centrifuge casting process is carried out considering sand as particle and its distribution is studied under water, for different viscosity values and for viscosity varying with respect to temperature. Based on centrifugal force and density difference, an attempt has been made to mathematically model the centrifuge casting force to estimate the particle distribution over the length of the specimen and also to assess the influence of process parameters such as rotational speed (G-force) and density of the particles.

Ti-50.2Ni-5Zr Shape Memory Alloy Square Rots Production by the Casting Technique

2014 ◽  
Vol 783-786 ◽  
pp. 2445-2449
Author(s):  
K. Kitamura
Keyword(s):  
Shape Memory ◽  
Centrifugal Casting ◽  
Xrd Analysis ◽  
Casting Technique ◽  
Shape Memory Behavior ◽  
Phase Constituent ◽  
Treatment Conditions ◽  
Shape Memory Effects ◽  
Cold Rolled ◽  
Deformation Stress

The purpose of this study is to make the Ti-Ni-Zr specimen using casting method from P/M ingot and evaluates the shape memory behavior. All samples were square rod shape made by centrifugal casting. The size of all samples was 1 mm wide, 1.3 mm height and 37.5 mm length. The transformation behavior during cooling and heating was investigated using a differential scanning calorimeter (DSC). The phase constituent was determined by XRD analysis from 20 °C to 150 °C. Mechanical properties of the shape memory effects were measured using a tensile machine at 25 °C. The samples were annealed at 400 °C, 500 °C and 600 °C for 3.6 ks followed by water quenching. After annealing, specimens were cold rolled at 0 % (no rolling) and 10 %. The Ti-Ni-Zr square rod specimens are fabricated by centrifugal casting using P/M ingot. All samples had shape memory behavior. From DSC measurement, the highest reverse martensitic transformation temperature is 120 °C. From tensile test, the Luders like deformation stress were not constant and dependence of heat treatment conditions was not clarified. However, 10% cold rolling specimen, shape memory characteristics were stabilized.

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