In this study, powders of gas atomized AA2014 and solid B4C were mixed and then used in an infiltration system. To attain particulate reinforced aluminum composites, fine particles of B4C were added in right proportions of 10% and 20% respectively. Micro structures of AA2014-B4C composite were then analyzed systematically, where at first hardness measurement were applied after liquid phase sintering, ageing and cryogenic cooling. Samples were then analyzed with scanning electron microscopy (SEM) techniques to determine the effect of several heat treatment steps on the microstructure. It was found that hardness values particularly obtained right after cryogenic cooling treatment were considerably higher than that of sintering and ageing treatments. These results show that, application of cryogenics may play an effective role in the behaviour of age-hardenable alloys.