Effect of dendritic or globular (rosette-like) morphology and its parameters on hardness of Al–7.5 wt% Si castings

Effect of dendritic and globular (rosette-like) morphology and its parameters on the hardness of Al–7.5% Si castings has been investigated. It was established that Brinell hardness demonstrates a slight increase with the rise of globules’ size and a slight decrease with the rise in dendrite parameter. In the first case, this is apparently due to isothermal holding in the process of obtaining castings, in the second case, with a decrease in the quenching rate of eutectics due to a decrease in the surface area of the dendrites because of coarsening.