The specific strengths of aluminum alloys are generally thos

The specific strengths of aluminum alloys are generally those of plain carbon steels. Higher than Lower than The same as Three types of cooling were performed as drawn on the isothermal transformation diagram (on next page) for a steel of cutectoid composition. Describe the possible microstructures and their (approximate) amount/percentage present in the steel at the end of each path. Cooling Path 1: Heat to 800 degree C and hold there for a long time, then slowly cool down to 650 degree C in a period of 1000s, then quench (or rapid coot) to room temperature. The resulting micro-microconstituents. 100% bainite 100% martensite 100% pearlite pearlite, 50% martensite Cooling Path 2: Heat to 800 degree C and hold there for a long time, then quench to 500 degree C and hold there for 1000s, and then quench to room temperature. The resulting micro-microconstituents: 100% bainite 100% martensite 100% pearlite 50% pearlite, 50% martensite Cooling Path 3: Heat to 800 degree C and hold there for a long time, then slowly cool down to 675 degree C in a period of 100s, and then quench to room temperature. The resulting micro-microconstituents: 100% bainite 100% martensite 100% pearlite 50% pearlite, 50% martensite

Solution

9) higher than

10) a) 1

b) 2

c) 3