Anodized Titanium Ring, Hard Coating For Ti6Al4V Needed ?

Q: Hi. I recently was married (last weekend) my wedding ring is made of Ti6Al4V, a Titanium alloy of high tensile strength. Not knowing very much about metallurgy, I had assumed that a strong metal would be very scratch-resistant also. Turns out that Ti6Al4V is actually a fairly "soft" metal, and is easily scratched. My wife's father is a chemist specializing in metal coatings and he told me that he could form a TiN (Titanium Nitride) layer on my ring in his lab; TiN is very "hard" and therefore scratch resistant. It also has a golden color, which could be nice ... In doing some research on my own I have discovered that there are a variety of hard Titanium compound coatings, including TiN, TiCN (Titanium Carbonitride), AlTiN (Aluminum Titanium Nitride), among others. It is important to me to get a coating that is as "hard" as possible - right now that looks like AlTiN, which is the hardest coating that I could find. However, it is black in color, which might be a little weird for a wedding ring. Also, I was informed by a company which does such a coating that the underlying metal must be very hard to support the coating, and that Ti6Al4V doesn't cut it. What I'm wondering is if any experts out there have any opinions on Titanium compound coatings and which would provide the most hardness and scratch resistance when applied to a Ti6Al4V ring.

A:There was one web site where I saw a *green* coating but I lost my bookmark to the site and I have no idea where it is. I think green would be *very* cool (it's my favorite color) but it's very hard to tell from small web pictures what it would really look like. When I had this ring made I was trying to get the strongest metal that I could practically have made into a ring. Now I want the hardest coating possible so that I have a ring which is very, very hard to bend or break and also very, very hard to scratch. I want to be able to take my wedding ring off, bounce it off the concrete, catch it in my hand, and have it be completely unaffected. And so I was hoping that some of you experts out there might have some advice to give on this topic. Also, if anyone knows of a company which does coatings in the New York City area, that would be awesome ... I'd love to be able to stop by one of these shops and examine the results of the coating directly. Try anodizing the ring. Forms TiO2 that is hard but no as hard as some of the other coatings but can be made thicker. I'm curious as to how you reached the strength conclusion about Ti6Al4V? Your current problem is indicative of how

a "Little bit of fact" can hurt you. Oh, I have fallen into a similar trap a time or two myself... usually in a field in which I know considerably less than I thought I did. Real easy to have happen. One can also anodize titanium producing an oxide surface film.The colour depends on the thickness of this film,but yellow through to green should be possible.I have a pair of cufflinks with an insert of a section of titanium polished and etched showing the grain structure and then anodized so that each grain is different shades of yellow,green and purple.I have had no problems with marking on these on the other hand I dont bounce them off the floor.