Nonferrous metals and alloys

Macrofractures of samples of silumin with a modified and an unmodified structure obtained in static loading were investigated. The fracture of the modified silumin had a flat silky relief. The location of the fracture surface at an angle of 45 ° to the axis of the load indicated that fracture is determined primarily by the tangential stresses. The unmodified silumin sample had a coarse and very rough fracture perpendicular to the loading axis. Consequently, fracture occurred under the action of normal stresses.