Microstructure and mechanical properties of Al matrix composites reinforced by TiN-coated β-Si₃N₄ whiskers

ABSTRACT

The poor wettability between the ceramic reinforcements and the metal matrix makes it difficult to realize the densification process of composites, which is severely detrimental to their mechanical properties. To improve the mechanical properties of Al matrix composites (AMCs) reinforced by β-Si₃N₄ whiskers (β-Si₃N₄w), we prepare TiN coating on the surface of β-Si₃N₄w via molten salt process, remarkably strengthening the interface bonding between Al matrix and β-Si₃N₄w. By optimizing the coating layer thickness, the bending strength of AMCs reinforced by TiN-coated β-Si₃N₄w reaches 439 MPa at 850°C, exhibiting remarkable enhancement relative to the composites without TiN coating (335MPa). Meanwhile, the interfacial test shows that TiN-coated β-Si₃N₄w is well bonded with the Al matrix, and no interfacial defects were detected. Moreover, the TiN coating with appropriate thickness can efficiently alleviate the agglomeration of β-Si₃N₄w, promote the densification of AMCs, and modify the Al/β-Si₃N₄w interface.

GRAPHICAL ABSTRACT

KEYWORDS:

• Al matrix composites
• TiN coating
• mechanical property
• interface
• β-Si₃N₄ whisker

Disclosure statement

We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, there is no professional or other personal interest of any nature or kind in any product, service, and/or company that could be construed as influencing the position presented in, or the review of, the manuscript entitled.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by National Key R&D Program of China (No. 2018YFF01013605, No. 2017YFB0406200), the National Natural Science Foundation of China (No.51501215), the Youth Innovation Promotion Association CAS (No.2019254), Science Foundation for Youth Scholar of State Key Laboratory of High-Performance Ceramics and Superfine Microstructures (SKL201701), State Key Laboratory of New Ceramic and Fine Processing Tsinghua University (KF201806).