Experimental investigation on microstructure and properties of Al alloy-PEEK joint with different surface structure obtained by hot-pressing

Abstract

In this study, selective laser melting (SLM) additive manufacturing was used for the fabrication of Al alloy with the surface structure based on the construction of mechanical interlocking mechanism to complete the joining with polyetheretherketone (PEEK). The application of hot-pressing process provided a direct joining between Al alloy-PEEK at 460 °C for 40 min. This work characterized the forming of both cylindrical and trapezoidal structures, indicating that the structures were formed completely, and the gaps were clear. Although some dimples or micropores were generated in the forming solid, these defects in the forming were beneficial for the flowing and filling of PEEK during hot-pressing joint. The microstructure of Al plate fabricated by SLM showed typical parallel columnar grains perpendicular to the deposition direction and stacked and fish scale like feature in the deposition direction, respectively. The microstructure characterizations of Al alloy-PEEK joints showed that both materials were joined without gaps and formed a strong mechanical interlocking, guaranteeing a firm bond with maximal tensile shear strength up to 81 MPa for trapezoidal structure. By comparison, the joint with cylindrical structure possessed a low 65 MPa shear strength due to weak cuneiform anchor interlocking. Fracture surface was investigated in more detail. The result showed that the joint with cylindrical structure mainly showed interfacial failure and pulling-out, tilting deformation and fracture of the supporting, while the joint with trapezoidal structure exhibited a separation between the top surface of the supporting and the PEEK and brittle cohesive fracture of the PEEK between the gaps.

Keywords:

• Additive manufacturing
• aluminum
• PEEK
• surface structure
• hot-pressing technology
• joint

Acknowledgements

This work was supported by the National Natural Science Foundation of China Youth Fund (51602081)

Author contributions

Conceptualization: [Baoxia Ma], [Yang Wang]; Methodology: [Baoxia Ma], [Yang Wang], [Yanhe Yang]; Software: [Yanhe Yang], [Yang Wang]; Validation: [Yanhe Yang], [Yang Xu], [Longfei Bi]; Formal analysis: [Baoxia Ma], [Yanhe Yang], [Yang Xu]; Investigation: [Yang Wang]; Resources: [Yanhe Yang], [Yang Wang]; Data curation: [Baoxia Ma], [Yanhe Yang]; Writing-original draft preparation: [Baoxia Ma], [Yanhe Yang]; Writing-review and editing: [Baoxia Ma], [Yanhe Yang]; Visualization: [Yang Xu], [Longfei Bi]; Supervision: [Baoxia Ma], [Yanhe Yang]; Project administration: [Baoxia Ma]; Funding acquisition: [Baoxia Ma]. All authors have read and agreed to the published version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms part of an ongoing study.