Corrosion Performance of Additively Manufactured Metallic Biomaterials: A Review

The growth of the elderly population and the high prevalence of cardiovascular and orthopedic diseases have increased the demand for biological materials. The combination of additive manufacturing (AM) and biomaterials holds promise, especially for patient-specific applications. Metal biomaterials are used in human medical equipment more than other families of materials. Corrosion resistance of implant materials is the main factor influencing their performance and durability and determining their biocompatibility. The basic paradigm for metallic biomaterials, with the exception of biodegradable metals, is that “the higher the corrosion resistance, the more biocompatible.” This study is a detailed, critical, and analytical review of previous studies and researches in the field of metals and alloys used as implant materials, including magnesium and its alloys, stainless steel, titanium and its alloys, etc. This study focuses on highlighting some of the basic principles for implant material fabrication that underlie the composition, structure, and properties of these materials. The specific conditions associated with the AM process are known to create fine microstructures in these materials with unique directional growth characteristics away from equilibrium. This unique microstructure, along with other special features and microstructural defects caused by the additive manufacturing process, has a significant effect on the corrosion behavior of these materials. Thus, this work provides an in-depth review of the previous work to date investigating the corrosion aspects of additively manufactured metallic biomaterials.