High Properties Metallic Alloys Obtained Through The Thermal Spray Route

摘要

For a long time now, atmospheric thermal spray has been used to produce a variety of protective coatings and even free standing shapes based particularly on ceramic materials using tailored powders. Although spraying metallic powders suffer from drawbacks arising from the oxidizing environment, it has also a number of applications. Unfortunately, the mechanical properties of the deposits are often lower than those of the corresponding bulk materials. With the development of "vacuum" or "low pressure" plasma spraying in the past two decades, new achievements have been obtained concerning the production of high mechanical properties metallic free standing parts. Meanwhile, this production route which necessitates the initial production of high grade alloyed feedstock powders remains expensive. The aim of this paper is to demonstrate that an alternative route, using blends of elemental powders, is promising both from the economical and metallurgical points of view. Such a process allows the production of metastable phases which are normally not obtained using the traditional metallurgical routes. These phases may lead to outstanding mechanical properties. Examples are given for titanium and copper based alloys.