Powder injection: The key to reconditioning and generating components using laser cladding

Abstract

Since the development of high power lasers cladding has been one of the major research topics. During the last fifteen years basic and applied research led to a profound understanding of the cladding process as well as to a variety of potential applications (1,2). However, industry was rather reluctant to adopt this technology, mainly due to high investment and running costs. Since high power diode lasers and diode pumped Nd:YAG lasers were developed and introduced to the market the situation has changed. A main advantage of these lasers is a significant reduction in running and maintenance costs (3). Apart from this progress is made in automation and process layout of laser cladding. These developments led to an increased request of industry for laser cladding especially for the repair of tools (4) and turbine engine parts (5). The next step will be the generation of complete prototype components and the geometric modification of expensive tools. In laser cladding the supply of the additive material is one of the key factors controlling the process. The most advantageous method is powder injection. However, the available equipment was developed for the needs of research institutions. New efforts were and still are necessary to provide equipment which meets the requirements of industry regarding aspects such as reliability, maintenance and lifetime. In this paper different concepts of powder injection will be discussed and some applications will be presented