Preparation, mechanical properties, and corrosion resistance behavior of (Zr, Mo, Cr)-doped Ti3AlC2 ceramics

The corrosion resistance of Ti3AlC2 is an indispensable characteristic in its practical applications, and the focus of this study is to optimize its mechanical and corrosion properties by introducing metal ions at the M-sites of Ti3AlC2. Utilizing Ti/Al/C/Zr/Mo/Cr powders, (Ti0.8X0.2)3AlC2 solid solutions were synthesized via reactive hot pressing, with XRD and SEM analyses confirming the formation of MAX phases. Results revealed varying degrees of influence on the properties of Ti3AlC2 due to different doping elements. Among these, Zr-doped samples exhibited superior mechanical properties, boasting excellent hardness (511 Hv), flexural strength (386.57 MPa), and fracture toughness (10.24 MPa m1/2). Additionally, all (Ti0.8X0.2)3AlC2 samples formed n-type semiconductor passive layers in 3.5% NaCl solution, demonstrating outstanding corrosion resistance. Further investigation revealed that the enhancement in mechanical properties stems from solid solution strengthening and lattice distortion induced by different metallic elements. Meanwhile, the corrosion resistance is primarily attributed to alterations in electron distribution resulting from doping elements. These stable materials could find applications in electroplating wastewater treatment, where materials with excellent mechanical properties and corrosion resistance are required. It is anticipated that further modifications of MAX phase materials through doping will meet these additional requirements.