Surface Structuring via Additive Manufacturing to Improve the Performance of Metal and Polymer Joints

Abstract

In order to enhance the joint performance of Ti6Al4V titanium alloy (TC4) and ultra-high molecular weight polyethylene (UHMWPE) for biomedical applications, different structures were fabricated on TC4 surfaces via electron beam melting (EBM) method in this study. Macromorphologies and microinterfaces of TC4–UHMWPE joints produced via hot pressing technique were carefully characterized and analyzed. The effects of different surface structures on mechanical properties and fractured surfaces were investigated and compared. Strong direct bonding (1751 N) between UHMWPE and TC4 was achieved. The interfacial bonding behavior of TC4–UHMWPE joints was further discussed. This study demonstrates the importance of combining macro- and micromechanical interlocking, which is a promising strategy for improving metal–polymer joint performance. It also provides guidance for metal surface structuring from both theoretical and practical perspectives.

Chemical Reaction and Bonding Mechanism at the Polymer–Metal Interface

“…The morphology of the metal surface plays an important role in the interfacial bonding between the metal and polymer, especially for the effect of microscale mechanical interlocking. , Figure a,b shows the typical 3D morphologies of the chromium-coated steel surface, which can be used for quantifying the surface roughness and topography. It is worth noting that the overall surface morphology of Cr-coated steel was relatively uniform, while there were numerous valleys and ridges on the surface.…”

“…As is well known, the performance and service life of polymer− metal hybrid structures are closely related to the interfacial structure and bonding mechanism. 10 In consequence, comprehensively analyzing and uncovering the interface are conducive to the optimization of the preparation process for products. According to the characterization results shown in preceding sections, it is revealed that EAA and steel were intimately bonded via the coated chromium layer.…”

“…Thus, it is critically important to clarify the underlying bonding mechanisms, which are the theoretical basis for further optimizing the interfacial bonding quality. 10 Specifically, analyzing the microstructures, chemical compositions, and phases at the interface of polymer−metal hybrid structures is a key issue that has attracted continuous and extensive attention. At present, various techniques and methodologies have been applied to study the interfacial structures, which helps to understand the interfacial bonding mechanisms.…”

“…), have a versatile application in aerospace, machinery, electrical, automotive, biomedical, food packaging, and many other fields. − However, due to the great difference in physical and chemical properties of polymers and metals, obtaining an interface with high quality is a challenge. Thus, it is critically important to clarify the underlying bonding mechanisms, which are the theoretical basis for further optimizing the interfacial bonding quality …”

Deposition of Biocompatible Polymers by 3D Printing (FDM) on Titanium Alloy

“…There are proposals to use 3D FDM printing to create metal-polymer joints, although they are based on 3D printing by applying polymers to polymers, thereby creating a rivet that holds the metal part [51]. Other additive manufacturing methods were used to create the surface shape of the metallic material to enhance the bonding force [52]. No papers have been found describing the direct application of plastic to metal by 3D FDM printing.…”