January_AMP_Digital

A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 2 0 2 8 TECHNICAL SPOTLIGHT Any product form that will fit in the tank can be conditioned by the MetCon process. As many pieces as the tank can hold can be treated at one time. PROCESSING BREAKTHROUGH IMPROVES TITANIUM YIELD A chance discovery is enabling significant efficiency gains in titanium conditioning, one of the most costly steps in titaniummetal production. W hen Jim Clasquin began ex- perimenting with titanium, he was trying to solve a specific problem: How to precisely color code the titanium components used in med- ical implant surgery. What he ended up discovering was the first major cost-sav- ing innovation for titanium processing in more than 25 years. This article sum- marizes Clasquin’s journey. COLOR CODING SURGICAL KITS Patients who need musculoskel- etal replacements come in different sizes, so the titanium implant compo- nents and surgical tools must be sized accordingly. For maximum safety and efficiency, manufacturers have devel- oped systems to assist in distinguishing the parts in a surgeon’s kit for different sized patients and specific procedures. Color coding, which can be an import- ant aspect of the differentiation, should be straightforward: Simply anodize the titanium implant components so they are color matched to the tools, instru- ments, and packaging. Yet the reality is not that simple. Consider that the various compo- nents used in a joint replacement sur- gery may all be produced by different methods—forging, casting, or CNC ma- chining—giving them different surface finishes. Unlike anodizing other metals where color is produced by surface dye coloration, anodization of titanium pro- duces an oxide layer that determines the color. The carefully controlled, ex- ceptionally thin oxide layer acts as a prism and the layer depth governs the color. Light bouncing off the layer inter- feres with light passing through it and reflected by the metal surface finish below. Because component surfaces vary depending on how they were pro- duced, the light returned through the prismatic oxidation layer of titanium anodized parts is perceived as different colors by the human eye. Clasquin, operating a surface fin- ishing and color anodizing business for medical parts and other industries, struggled to produce matching colors for components with different finishes. During the day, he followed strict pro- cedures required by his medical com- ponent customers. But after hours, he kept searching for a way to make the titanium surfaces uniformly smooth regardless of how they were manufac- tured in order to produce a uniform and matching color. He was familiar with methods of passivating stainless steel using mild acids and controlling titanium anodization with rectifica- tion, so this is where he started. His goal was to suggest alternative surface preparation methods for his customers to evaluate, potentially leading to bet- ter color anodizing procedures across the industry. TREATING TITANIUM SURFACES Because Clasquin is a chemical en- gineer, he never studied how to treat ti- tanium surfaces, as many metallurgical engineers do. If he had, he would have been taught that titanium only reacts to aggressive acids that must be han- dled with specialized equipment and extreme caution. Due to the natural cor- rosion resistance of titanium and where the metal ranks on the electrochem- ical tables, it has long been accepted