Structural materials that are intended for service at very high temperatures are usually strengthened by precipitation hardening, using precipitates that involve substitutional solute species. Examples include the Fe-based and Ni-based 'superalloys' used in jet engines, which are strengthened by precipitates of intermetallic compounds such as Ni3Ti. Why choose precipitation hardening? Why should the precipitates employ substitutional solutes?

If this is a true or galse then its true but if not then what is the question?

Answer is: the equilibrium  shifts toward the reactants, to the left side of chemical reaction.it is because lead(ii) nitrate dissociates in water: pb(no₃)₂ → pb²⁺(aq) + 2no₃⁻(aq).according to lechatelier's principle, the position of equilibrium moves to counteract thechange (more lead cations, common ion), the position of equilibrium will move so that the concentration ofproducts decrease and concentration of reactants of chemical reaction increase.read more on -