Effect of slope plate variable and reheating on the semi-solid structure of ductile cast iron

Semi-solid metal processing with the cooling plate technique is one of the key technologies for producing advanced materials. The multitude of cast iron families with their wide range of mechanical properties, and relatively low costs combined with the advantage of semi-solid processing allow production of high quality cast components from cast iron. The effect of semi-solid processing using the cooling plate technique on the microstructure and the properties of cast iron is studied. The investigated material is hypo-eutectic, hyper-eutectic gray iron, compacted graphite and ductile cast iron. The results indicated that the microstructure (primary austenite and graphite) becomes finer and more globular by increasing the fraction of solid. The tensile strength of semi-solid processed cast iron is relatively high compared with ordinary cast iron. The values of both the tensile strength and the elongation depend on the fraction of solid. The total fracture strength is observed to depend on the graphite morphology as well as the matrix contribution that mainly depends on fraction of solid. The wear resistance and damping capacity of cast iron were investigated as a function of the relative amount of primary fraction of solid.

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The Role of Alloy Design in Semi-Solid Casting of Ductile Iron Processed by Inclined Cooling Plate

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.457.287 ◽

2010 ◽

Vol 457 ◽

pp. 287-292 ◽

Cited By ~ 1

Author(s):

Bashir Heidarian ◽

Mahmoud Nili-Ahmadabadi ◽

Marzyeh Moradi

Keyword(s):

Cast Iron ◽

Reliable Method ◽

Ductile Cast Iron ◽

Forming Process ◽

Plate Method ◽

Equilibrium Conditions ◽

Cooling Plate ◽

Solidification Range ◽

Semi Solid

The inclined Cooling Plate process can be considered as a reliable method for the production of semi-solid ductile cast iron. By utilizing aforesaid method, the main limitation of common semi-solid methods, i.e. Mg fading, will be eliminated. The present research is intended that the importance of alloying design through the inclined cooling plate method and its profound effect on obtaining the optimum solidification range for thixo-forming process have been illustrated. The optimization of solidification range for thixo-forming process has been gained by the simulation in both equilibrium and non-equilibrium conditions. Afterwards the alloy selection has been performed amongst several alloying composition with a view to their effect on the thixo-forming process and austempering.

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Kinetics of Coarsening and Solid Sphericity during Reheating of Ductile Iron and Al Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.205 ◽

2006 ◽

Vol 116-117 ◽

pp. 205-208 ◽

Cited By ~ 8

Author(s):

P. Babaghorbani ◽

S. Salarfar ◽

Mahmoud Nili-Ahmadabadi

Keyword(s):

Cast Iron ◽

Solid State ◽

Ostwald Ripening ◽

Ductile Cast Iron ◽

Al Alloys ◽

Solid Particles ◽

Coarsening Kinetics ◽

Semi Solid ◽

Reheating Process ◽

Kinetics Of

Reheating process in the semi-solid state is a very important step in the thixoforming process. In this research semi-solid ductile cast iron and Al alloys (Al-2.5Si, Al356) prepared by inclined plate method, were reheated to examine the effect of reheating conditions on the microstructure and coarsening kinetics of the alloys. For ductile cast iron, solid fraction at different reheating temperatures and holding times was obtained and based on these results the optimum reheating temperature range was determined. In the case of Al alloys increase of holding time in the semi-solid state, leads to increase of liquid fraction, solid grain size and improvement of sphericity of solid particles. In addition, the results show that coarsening kinetics of microstructures of both alloys during reheating was diffusion controlled and can be mostly treated by Ostwald ripening theory.

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