# title
Structural, physical and mechanical properties of Ti₃(Al1-xSix)C₂ solid solution with x=0-1

# abstract
2016 Elsevier B.V.  A series of high-purity Ti 3 (Al 1x Si x )C 2 solid solutions with 0<x<1 were reaction sintered from Ti, Si, Al and TiC powders using Pulsed Electric Current Sintering (PECS). 1 The a-lattice parameter of all sintered solid solutions remains constant at approximately 0.307nm, while the c-lattice parameter decreases from 1.858nm to 1.763nm with increasing amount of Si. The specific heat capacity of Ti 3 Al 0. 6Si 0.4 C 2 was found to be comparable to that of end-member MAX phases, namely Ti 3 AlC 2 and Ti 3 SiC 2, while its coefficient of thermal expansion (CTE) was lower than that of the end members. Both Young's and shear moduli increase with increasing amount of Si. Vickers hardness (H v ) measurements demonstrate significant hardening effect in Ti 3 (Al 1x Si x )C 2 solid solutions regardless of the grain size, i.e. it changes from 4.10.14GPa of Ti 3 AlC 2 and 4.20.37GPa of Ti 3 SiC 2 , up to 5.60.2GPa for Ti 3 (Al 0.4 Si 0.6 )C 2 . At room temperature, the strengthening effect was found to be marginal in the fine grained structure (grain size approximately 7 x 3 m), as the compressive strength of Ti 3 Al 0.6 Si 0.4 C 2 and Ti 3 Al 0.4 Si 0.6 C 2 is higher for only 7.6% when compared to that of the end members. However, significant strengthening effect was observed in coarse grained structures (grain size approximately 25 x 8 m) as the room temperature compressive strength of solid solutions exceed those of two end-members for more than 30%. Nevertheless, above brittle-to-plastic transition temperature, the solid solution strengthening effect diminishes and the strength of Ti 3 SiC 2 is significantly higher than that of Ti 3 AlC 2 and solid solutions. Finally, it was found that Ti 3 Al 0.6 Si 0.4 C 2 forms protective alumina oxide layer at 1200C, rather than silica that is commonly found on oxidized surfaces of Ti 3 SiC 2 .

# publicationOutlet
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

# authors[].organizations[].label
Texas A&M Engineering Experiment Station (TEES)

# authors[].organizations[].label
Institute for Engineering Education and Innovation

# authors[].organizations[].label
Texas A&M Engineering Experiment Station (TEES)

# authorList[]
Gao, H., Benitez, R., Son, W., Arroyave, R., & Radovic, M.