Hot Forging of Semi Solidified High Strength Brass

Abstract

The name “high strength brass” is given to the wrought and cast alloys indicating their particular virtue of high strength, which can be achieved by additions of Al, Fe, Mn and Sn. Forgings made from copper base alloys offer a number of advantages over products made by other processes. However, because for forging more heat must be applied to the ingot which was solidified once, there are some disadvantages in the economy of energy and time. In this study, we investigated the microstructures and mechanical properties of high strength brass made by semi solid forging and compared them with those of conventionally forged product and gravity die casting. No shrinkage or gas hole was found in semi solid forgings. Fine equiaxed crystals developed at the center of semi solid forgings, while grains in the corner of semi solid forgings were elongated perpendicular to the pressure direction. The grains of semi solid forgings were smaller than those of conventional forgings and gravity die castings. It is suggested that a rapid heat transfer condition due to applied pressure is responsible for grain refinement. Tensile and yield strengths of semi solid forgings were as high as those of hot forgings but elongation was positioned between that of conventional forgings and gravity die castings.