相图是用以表示相平衡以及相变化的几何图形,也可以认为它是研究相平衡及其变化的工具。相平衡则表示一物系固——固、固——液和液——液之间在各种温度下共存以及彼此间相互消长的情况。简言之,相平衡表示了相组成及其数量随温度的变化关系,因而相图能够对生产实际 A phase diagram is a geometric figure used to represent phase balance and phase change. It can also be considered as a tool to study phase equilibrium and its changes. Phase equilibrium means that a solid-solid, solid-liquid and liquid-liquid co-exist at various temperatures and the mutual growth and decline between each other. In short, the phase equilibrium shows the phase composition and the amount of change with temperature, so the phase diagram can produce real