Journal of Materials Processing Technology 143–144 (2003) 270–276 Static analysis of the guiding bearing drill contact by finite element method I. Ciupitu ∗ , N. Dumitru, St. Gheorghe, C. Teisanu Fac. De Mecanica, CATEDRA TCM-MU, University of Craiova, Str. Calea Bucuresti nr 165, Craiova 1100, Romania Abstract In this paper are presented the results obtained by the analysis of a guiding bush–drill system when is processed by cutting. The guiding bush is performed by metallurgy of iron–copper and graphite powder mixtures. For the analysis by finite elements method were determined experimentally the mechanical specific features of samples performed from considered powder mixture. The cutting force and the cutting torque were determined in drilling process of a semi-finished product obtained from 65Mn10 material, using for drill guiding sintering bush. Using the finite elements method, the tensions were obtained, the deformations and the movements in guiding bush–drill system. © 2003 Elsevier Science B.V. All rights reserved. Keywords: Powder metallurgy; Guiding bearing; Finite element method 1. Introduction Powder mixtures represent the easiest way of obtaining an alloy as the users of powder are being able to produce the wanted alloy and modify it according to their own needs. The iron powders have a special importance in used mix- tures for achievement of a product with good mechanical properties. These powders have good plasticity, providing good compressibility (resulting in high density) and a good strength for the obtained untreated pressed part, in the press- ing process. The iron powders used in the studied powders mixtures are powders from current production of S.C. Ductil S.A., Buzau [1]. The copper powder type PCu99.5 used is obtained by electrolysis. Graphite type F95 is obtained from graphite with a carbon concentration no more than 30%, using me- chanical processes of preparing. The increasing of carbon content is realized mainly by floating, after they are ob- tained by hydraulically or pneumatically classifying. Dried natural graphite type F95, I quality, sort 4 was used. The graphite powder is realized at Salrom—Exploatarea Miniera Ramnicu-Valcea Romania. In the iron–copper–graphite mixtures, iron represents ba- sically the amount which is added to the copper powder in order to increase the mechanical strength of sintered pow- der parts. The graphite powder added to the iron–copper ∗ Corresponding author. mixture decreases the parts dilatation during the sintering process. The copper powder in the iron–copper mixture influences the dimensional instability of the sintered powder part. The dilatation of created sintered powder parts with the copper reaches value over 1% for more than 4% copper [2]. The use of graphite in the iron–copper mixture permits the dilatation decreasing by iron–copper–carbon eutectic forming, rich in iron, with melting temperature around 1100 ◦ C. The dimensional variation of sintered powder parts made of iron–copper–graphite is minimum for compositions up to 5% copper for 1% graphite. For realizing study of some sintered powder parts with good mechanical and wear strength, we considered the following powder mixtures: 94% iron + 5% copper + 1% graphite. 2. The mechanical characteristics of ferrous sintering alloys For the study of mechanical characteristics like tensile strength, compression strength, static strength and strength under shock, I have used typical samples compacted with a 600 MPa applied uniaxial pressure. The samples were per- formed inside a vacuum chamber that was introduced into an electrical oven with a maximum temperature of 1200 ◦ C. The tests results are presented in Table 1, [3]. 0924-0136/$ – see front matter © 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0924-0136(03)00470-9