Phase diagrams of binary and multicomponent systems are the basis of modern alloy theory. The ability to use them in solving various practical problems is a necessary part of material scientists training. The skills and knowledge acquired during the course will help you to: • create new alloys and improving the existing ones; • modernize metallurgical processes for obtaining metals and compounds and cleaning them from impurities; • optimize technologies for the production of blanks from these alloys; • research the coatings, surfacing, castings, etc. Phase diagrams contain the necessary information about the alloys composition under equilibrium or close to them conditions and about the temperatures of the beginning and end of phase transformations. The course will acquaint you with the phase transformations that occur in alloys of binary phase diagrams. By the end of the course you: • will know all types of binary phase diagrams; • will analyze the transformations of any alloy in equilibrium and non-equilibrium conditions; • will assess the volume fraction and composition of phases; • will describe the structure of different alloys; • will choose heat treatment modes to eliminate the non-equilibrium structure. You may find some of the themes challenging, but we have included many visual material to help you master this course.