To what factors would you attribute the fact that the coefficient of friction in hot working is higher than in cold working? Q2. How can adhesive wear be reduced? Q3. Wear can have detrimental effects on engineering components, tools, dies, etc. Can you visualize situations in which wear could be beneficial? Give two examples. Q4. The end of a rod made of hardened steel (hardness 1420 N/mm2, 1 mm in diameter) slides over a lubricated hardened steel surface. The rod is normal to the steel surface and pushes against it with a load of 500 N. The rod needs to travel what distance [km] to result in adhesive wear of 600 m? Q5. Why is the abrasive wear resistance of a material a function of its hardness? Q6. The abrasive wear can be reduced by increasing the hardness of softer materials or by modifying the processing parameters of load and sliding speed. In addition, use of very compliant materials, such as elastomers, might help reduce the abrasive wear. Explain the mechanism of this phenomenon behind this. Q7. How can fatigue wear be reduced? List three approaches. Q8. What are some of the important reasons why manufactured parts must be cleaned