In compression test, the fracture in cast iron specimen would occur along

Explanation:

• Cast iron is very strong in compression but weak in shear.
• When a cast iron specimen is subjected to a compression test a plane inclined at 45o to the normal plane has shear stresses due to a resolved compression force.
• Thus this plane is subjected to shear stress.
• As cast iron is weak in shear, failure occurs along this inclined plane.
• The first below figure is showing how shear will cause an oblique plane fracture.
• The second figure is showing a fracture plane in cast iron due to tensile and compressive loading respectively.
• The third figure is showing the cup and cone fracture in ductile materials in the tension test.

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