P 975 – Improvement of Wear Properties of Hot-Forming Tools by Laser-Deposition-Welding of Carbides
The increasing integration of functions in unity with optimized weight leads to an increasing complexity of components and the use of high-strength and ultra high-strength materials.
In this context, hot forming is often the only economical manufacturing process for the production of such components. In the field of manufacture of complex shaped components, forging holds a special position within the hot forming manufacture processes.
For mass production of forged parts often multistage hot presses are used, in which the components are manufactured in several stages in processes linked by cams within one machine.
This linkage, however, at the same time states the demand for an as-high-as-possible lifetime of all tools involved in the production processes, because the breakdown of one tool leads to a stop of the whole machine.
Considering this background, the high stressed cutting tools which portion the fed bars get into focus. These cutting tools have been enhanced in the past, so that there are several stages of evolution, some of which are used in parallel because of the cost situation.
A still good practice for wear protecting with resulting increase of lifetime is the coating of cutting tools with standard heat resistant hard alloys. Here, the used coating material is still a variable factor that holds great potential for optimization.
In the present project, first the causes of wear and the detailed charateristics of the tool wear are examined and reconstructed in order to define the layer requirements and the associated requirements for the coating material.
Moreover it is shown in studies that in addition to the material itself, the choice of the coating process plays a significant role for the layer properties. For example, the investigated laser cladding compared to the standard used manual methods leads to a much finer microstructure of the layers.
The mentioned factors are variables in the optimization process of the cutting tools, for which reason within this short project a test facility is designed in order to provide a costeffective and reproducible investigation of coating materials and coating processes. With this test facility the load profile of the cutting tools can be simulated. The aim of the test facility development is the study of the effects of material-related but also procedural variables on the wear behavior of the cutting tools.
Only available in german language.
R. Wahl, A. Baum
FOSTA – Research Association for Steel Application