Improving the life cycle of forging dies with active brazed ceramic inserts Fr.-W. Bach, E. Doege, I. Kutlu and A. Huskic University of Hanover, Germany Corresponding author: E-mail:huskic@ifum.uni-hannover.de Abstract: The use of embedded ceramic inserts in forging tools has lately been investigated and successfully tested with model forging dies. However, there is a danger of the mechanical widening of the steel tool as a major problem of forg- ing dies with embedded ceramic inserts. Furthermore, only rotation symmetric ceramic inserts can be embedded, which allows only a small variety in the con- struction of tools. A considerably larger number of designs are possible for active metal brazing of ceramic inserts in the die’s body material. For achieving this, active brazed ceramic–metal compounds were developed and tested for their practical use in the forging process. Keywords: Active metal brazing, ceramic inserts, forging dies, wear reduction. Reference to this paper should be made as follows: Bach, Fr.-W., Doege, E., Kutlu, I. and Huskic, A. (2003) ‘Improving the life cycle of forging dies with active brazed ceramic inserts’, Int. J. of Materials & Product Technology, Vol. 19, No. 5, pp. 351–361. 1 Introduction Forging dies have to endure high thermal and mechanical stresses. These stresses cause wear of the forging dies and reduce the dimensional accuracy and quality of the forged parts until the tools must be changed. At forging temperatures of 1250° C and base tool temperatures of about 200° C the tempering temperature of the tool material (hot-work steel) will be exceeded at some points with high relative motions of the work piece mate- rial. This reduces the hardness and, therefore, the resistance against abrasive wear drops. In many cases this leads to very short lifetimes of the forging dies [1]. Concerning an extension of lifetime for forging dies and, therefore, extending the pro- ductivity of a forging plant, the use of new materials like ceramic provides an important alternative to conventional dies made from hot-work steels. Other areas of technology are already familiar with solutions for reducing wear, which are based on the use of ceram- ics. These highly wear resistant materials are used in wear-critical areas of different tech- nical applications because they have a great hardness and great thermal endurance capacity [2, 3]. Especially in machining technologies ceramic materials are used success- fully. The high machining capacity of ceramics compensates the higher costs for ceramic materials with extended lifetimes [4, 5]. In metal forming, ceramics were investigated for the isothermal forging of titanium and nickel-based alloys at temperatures above 1100° C on segmented as well as on solid 111 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 2011 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 3 4 5 6 711 Int. J. of Materials & Product Technology, Vol. 19, No. 5, 2003 351 Copyright © 2003 Inderscience Enterprises Ltd. Huskic 16/4/03 10:57 pm Page 351