Titanium PM was discussed in several sessions, including a Special Interest Program, during POWDERMET 2015 in San Diego. Presentations from USA, Sweden and Japan are summarized in this overview.
The Special interest program on Light Metals that took place at the POWDERMET 2015 Conference in San Diego covered developments in PM aluminum (see previous article, MPR July/Aug. 2015 issue) as well as magnesium and titanium. The past, present and future of PM titanium was appropriately presented by a veteran of the industry, Ms Susan Abkowitz, General Manager of RTI Advanced Powder Materials,formerly DynametTechnology Inc. She began by pointing out that Titanium PM went all the way back to the Kroll process for the primary extraction of metallic titanium. Some of the key processes developed in the early days still continue to be improved and achieve lower cost and growing volumes. These include rotating electrode powder production of spherical powder that evolved into the PREP process, as well as gas atomization. Early on, the Hunter process for producing sponge titanium by sodium reduction was a source of unwanted fines as a bi-product, which is where Dynamet Technology began with the idea of making PM parts from inexpensive powder. They created the alloys by blending elemental powders and developed the CHIP process, a combination of cold and hot isostatic pressing.
Abkowitz went on to refer to the several interesting processes being developed for the production of lower-cost titanium powder, some of which may become successful. On the PM product side, metal injection molding of titanium has been of interest in the manufacture of high-volume small parts for a long time, and now additive manufacturing is also drawing wide interest. Abkowitz did not see all these processes as competing with each other–rather they were all part of a broad spectrum of materials, shapes, products and market areas that will continue the use of PM titanium. Her company's CHIP approach was “to use the least expensive materials, keep the process as robust as possible, [avoid] prealloyed material…making blended Ti-6-4 alloy or other desired composition–even ones that cannot be made by melting due to disparate melting points or density”.
This article appeared in the Jan/Feb issue of Metal Powder Report.
