Abstract—The major disadvantage of coarse grain structure in castings is that it may result in a variety of surface defects and cracking. Non-uniformity of grain size also reduces the fatigue performance, yield strength and tensile elongation to fracture. A review made in the present study highlights the important methods of grain refinement for ferrous casting alloys. It has been shown that the processes used for the grain refinement of ferrous alloys require different types of techniques for the ferrous alloys with different carbon weight percentage. Techniques used for the refinement of ferrous alloys are equal channel angular pressing (ECAP), transformational grain refinement (TGR), current pulsing technique, conventional graphitising inoculant technique. It has been shown that grain refinement by using different techniques results in fracture toughness and high strength combination, improvement in low cycle, fatigue life, uniformity of properties, better feeding to eliminate shrinkage porosity and improved ability to achieve a uniform anodized surface. It has also been shown that grain refinement does not change the phase constitution, freezing characteristics and structural stability of the alloy and the stress rupture life of fine grained alloy sample is much better than that of conventional one. It has also been shown that there exists a relationship between the amount of grain refinement and the mechanical properties, which also depend on the refining method employed.

Index Terms—Cast alloys, Grain refinement, Grain structure, Mechanical properties

Cite:Khyati Tamta and D B Karunakar, "Grain Refinement of Cast Alloys: A Review," International Journal of Mechanical Engineering and Robotics Research, Special Issue, Vol. 1, No. 1, pp. 199-212, January 2014.