संरचनात्मक और इंजीनियरिंग सामग्रियों में थकान विफलता (Fatigue failure) मुख्य रूप से किस प्रकार के लोडिंग के कारण होती है?

Match the following alloying elements with their effects on the properties of steel: A. Copper - (iii) Improves corrosion resistance but reduces ductility B. Nickel - (i) Improves impact toughness and cold brittle tendency C. Manganese - (iv) Increases strength but reduces weldability D. Aluminium - (ii) Increases strength Select the correct match:

Which of the following is NOT classified as a fundamental engineering property category of materials?