The enthalpies of atomization of the transition metals are high.

Enthalpies of atomization is the enthalpy change when 1 mol of gaseous atoms is formed from its element in its defined physical state under standard conditions (298.15K, 1 atm). In case of the transition metals enthalpies are high due to high effective nuclear charge and a large number of valence electrons which also leads to strong metallic bonding.

Eg: 515 KJ/mol for for Vanadium,473 KJ/mol for Titanium