What is the typical dislocation density of metals which have

What is the typical dislocation density of metals which have been carefully solidified? 10^3 to 10^6 mm^2. 10^6 to 10^9 mm^-2. 10^9 to 10^10 mm^-2. 10^11 to 10^16 mm^-2. Which of the following will improve a material\'s strength? Cooling the molten metal slowly. Cooling the molten metal rapidly. Holding the metal at very low temperatures for a period of time. Applying repetitive tensile and compressive stresses on the material.

Solution

1.the typical dislocation density of material is 10^6 to 10^9 mm^-2

2. the strength of the material will improve by holding the metal at very low temperature for a period of time