Explain the terms a eutetic b hypoeutectic c hypereutectic d

Explain the terms (a) eutetic, (b) hypoeutectic, (c) hypereutectic, (d) eutectoid, (e) hypoeutectic (f) hypereutectoid, and (g) paratactic.

Solution

Eutectic : a mixture of substances (in fixed proportions) that melts and freezes at a single temperature that is lower than the melting points of the separate constituents or of any other mixture of them.

Hypereutectic: A metallic alloy which has a composition beyond the eutectic point. or When the composition of an alloy places it to the right of the eutectic point it is called hyper-eutectic.

Eutectoid: an alloy which has a minimum transformation temperature between a solid solution and a simple mixture of metals.

Hypo-eutectoid : steel has less than 0,8% of C in its composition. It is composed by pearlite and -ferrite. Hyper-eutectoid steel has between 0.8% and 2% of C, composed by pearlite and cementite.

Peritectic : A peritectic reaction is a reaction where a solid phase and liquid phase will together form a second solid phase at a particular temperature and composition .