en Research Paper Research Paper The effect of aging time and temperature on the microstructure and mechanical properties of Ti-13V-11Cr-3Al and Ti-13V-11Cr-3Al-0.2C was studied. The carbon addition increases the rate of age hardening as well as the peak hardness of aged samples. The presence of titanium carbides in Ti-13V-11Cr-3Al-0.2C limits grain growth during the process. The observations in this work are discussed in terms of the effect of the microstructural changes in quenched and aged samples associated with the presence of carbide precipitates Ti-13V-11Cr-3Al Alloy, Carbon content, Age Hardening 40 47 http://ijmse.iust.ac.ir/browse.php?a_code=A-10-3-190&slc_lang=en&sid=1 E. Mousavi E_mousavi@metaleng.iust.ac.ir 180031947532846002672 180031947532846002672 Yes School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. M. R. Aboutalebi 180031947532846002673 180031947532846002673 No School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. S. H. Seyedein 180031947532846002674 180031947532846002674 No School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran. S. M. Abbasi 180031947532846002675 180031947532846002675 No School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran, Iran.