Well, Christmas over and it is on to a new year. However, some things of the past are reluctant to leave us. In this case Aerospace is a good example. Way back, over 30 years ago, I was directed to develop the first powder metallurgy superalloys that had less than 100 ppm oxygen surface contamination. We were sucessful in introducing a powder form of Udimet 700 and B1900 that satisfied this criteria. As far as I know, these compositions are still the alloys of choice for turbine wheels. What this says is that it has been a long time since there has been meaningful improvement for alloys designated for aerospace applications. Yet the wish is to fly higher and faster in both commercial and space requirements. The current nickel and cobalt base superalloys will not permit this because of surface deterioration or microstructural change, deteriorating required properties. In addition, surface deterioration due to erosion and corrosion is one of the most expensive problems in the materials world that requires solution. Perhaps 2016 may be the year for at least some advances to be made.
Advanced manufacturing is bringing in completely new concepts to the materials world. It is only recently that people have started thinking of creating alloys by melting incremental layers of powder to create shapes not possible before. In the past, there was always the consideration of material removal to create the desired shape. In turbine components, as much as 85 % of the starting expensive superalloy material was removed to obtain the desired component. Today, using advanced manufacturing, vanes can be created that are not only to shape, but that can also have internal passages not capable of being created in the past to permit cooling of the aircraft turbine while activated.
This technology is still in initial stages of development. It requires complex three dimensional computer programming and either laser beam or electron beam apparatus to permit melting of powder layers of micrometer thickness, using a highly directional beam of energy to melt these layers incrementally. Using this technology, both inside and outside dimensions can be changed according to the needs of the component being created. This cost of the equipment, $1,000,000, limits the usage of the process. However, more and more components are being created using the new technology. It is particuarly useful if only one item or a few are required.
In addition to the above, the creation of powders to satisfy the property requirements of the component being created has been limited in chemical composition, and they too are expensive. However, as demand increases so too does the inventory of new powders of desired chemical composition.
Therefore, the beginning of a new year is always an exciting time. People make their wish lists at this time. It certainly will be exciting to see, as the year develops, how much advancement will be made to innovate new equipment and powder to continue to create parts not possible before, and at lower cost with less threat to the environment. Yes, 2016 looks to be a year where major problems may be resolved.