The cutter bars of two combine harvesters from differentmanufactures develop different failure types with time. Cutter barA loses the knife sharpening after 10 seasons, while cutter bar Bdoes not lose the knife sharpening but some blades have to bereplaced time to time due to local fracture of the edge. Throughmeasuring the volume and the weight the density of both blades arearound 7.8 – 7.9 Kg/dm3. The hardness of the blades fromA is 2.2 GPa while the hardness of the blades from B is 8 GPa.Discuss two possible manufacturing differences that would lead tothis situation. Use suitable references to support your discussion.Suggest two possible technologies to improve the life for bar A.Suggest a way to reduce the brittleness of bar B. Justify yoursuggestions and compare with real examples if possible.
[Hint] Use heat treatment graphs,composition-mechanical properties, material data, surfaceengineering…
