Nanocrystalline MAX/Mg Composites with Exceptional Properties
Abstract
Understanding the microstructure and mechanical properties of Mg-MAX composites Composites were fabricated by pressureless melt infiltration of Mg and Mg alloys into TiC and Ti2AlC porous preforms. Ti2AlC is a layered machinable ternary carbide (MAX), which is relatively light and stiff. Pure Mg and three Al-containing Mg alloys, AZ31, AZ61 and AZ91 were used as matrices. When the matrix Al content was ? 6 wt.%, the best mechanical properties were achieved for all the composites fabricated. We also studied the effect of reinforcement particle size. For fine-grained reinforcements - 50 vol.% TiC-AZ61 - the elastic modulus was 175+-5 GPa, Vickers hardness was 34+-0.3 GPa, and the ultimate compressive strengths was 1028+-5 MPa. The enhancements in elastic and mechanical properties are attributed to finer grained Mg-matrices, the presence of Al in the matrices which enhances the wetting TiC and Ti2AlC by Mg to create strong interfaces and finer reinforcement particle sizes, that lead to a better mechanical interlocking. In addition, due to Ti2AlC inherent mechanical energy dissipation, damping properties of Mg-Ti2AlC composites were measured to be higher than their TiC reinforcement counterparts. Quite recently we discovered a new micromechanism in the deformation of layered solids; bulk ripplocations, whose existence will upend much of our understanding of the deformation of layered solids.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 04, 2017
- Accession Number
- AD1053767
Entities
People
- Michel Barsoum
Organizations
- Drexel University