a)What is the name given to this "transformation"? b)What is the driving force? c)Write an equation for the rate of this transformation (assume diffusion control and explain what would contribute to variation of the rate with temperature. 49 a)Currently,directionally solidified eutectic alloys are used as improved strength turbine blade materials.What is the basis for their high strength?What problems are encountered in their manufacture? b)Why do oxide-dispersion-strengthened alloys exhibit high strength at elevated temperatures?What are the problems with ODS? c)Apparently,the next incremental improvement in turbine materials will be obtained from parts (disks,blade,vanes,etc.)fabricated by hot-isostatic-compression of alloy powder to near final shape.Discuss the economics and physical metallurgy for the use of such parts. d)In the use of stainless steels and other Cr203-forming alloys at elevated temperatures to contain the produces of combustion of fossile fuels,what special corrosion problems arise? 50.a)How does stacking fault energy influence cross-slip?What materials should manifest easy cross-slip?How does cross-slip affect a stress-strain curve? b)What is the equilibrium configuration of two edge dislocation lying in a soft metal plate coherently bonded to very hard ceramic plates on either side.The dislocation lines are parallel to the plate surfaces,their burgers vector is perpendicular to the plate surfaces.a) What is the name given to this “transformation”? b) What is the driving force? c) Write an equation for the rate of this transformation (assume diffusion control ) and explain what would contribute to variation of the rate with temperature. 49 a) Currently, directionally solidified eutectic alloys are used as improved strength turbine blade materials. What is the basis for their high strength? What problems are encountered in their manufacture? b) Why do oxide-dispersion-strengthened alloys exhibit high strength at elevated temperatures? What are the problems with ODS? c) Apparently, the next incremental improvement in turbine materials will be obtained from parts (disks, blade, vanes, etc.) fabricated by hot-isostatic-compression of alloy powder to near final shape. Discuss the economics and physical metallurgy for the use of such parts. d) In the use of stainless steels and other Cr203-forming alloys at elevated temperatures to contain the produces of combustion of fossile fuels, what special corrosion problems arise? 50. a) How does stacking fault energy influence cross-slip? What materials should manifest easy cross-slip? How does cross-slip affect a stress-strain curve? b) What is the equilibrium configuration of two edge dislocation lying in a soft metal plate coherently bonded to very hard ceramic plates on either side. The dislocation lines are parallel to the plate surfaces, their burgers vector is perpendicular to the plate surfaces