ABSTRACT
The presence of one or more intermediate phases (either binary or ternary) in addition to three primary solid solutions (or pure components) leads to many possible forms of ternary system. In this chapter, several examples are discussed, but the space models depict only the liquidus features and not the phase regions within the models. It is possible for a ternary system to contain one invariant peritectic reaction and one invariant eutectic reaction, instead of containing two invariant eutectics. In the hypothetical system ABC that is discussed in the chapter, in the solid state, the system is divided into the two regions AXC and BXC as in the case previously discussed, and section XC is not quasi-binary. All alloys within the region AXhC undergo the peritectic reaction and, depending on whether an alloy lies within the triangle AXC or XhC, either the liquid or component A is consumed.
