3 articles here that should help
http://www.azom.com/details.asp?ArticleID=1177
http://www.azom.com/details.asp?ArticleID=1146
http://www.azom.com/details.asp?ArticleID=470
or try this http://www.azom.com/SearchResults.asp?cbxNews=n&cbxArticles=a&MatKeyWord=titanium&AppKeyWord=&IndKeyWord=&Search=Search&Units=SI&MatProp1=&MathOperation_1=le&MatValue1=&MatProp2=&MathOperation_2=ge&MatValue2=