Tribological characteristics of stamping dies with coatings

A variety of cast iron and steel grades are used for manufacturing dies in stamping industry. The costs of these materials may vary considerably. However, with appropriate surface treatments, coatings and lubricants, a cost-effective die material may outperform the expensive ones. Therefore, in selecting die materials, a systematic evaluation of tool materials, coatings and heat treatments are required, considering the cost and tool life as parameters. In the contribution the plasma sprayed ceramic coatings Cr203 and Al2O3 were investigated in sliding contact with steel in both, the block-on-ring arrangement (tester T 05) and deep drawing process. The friction coefficient and wear of these coatings were measured at dry friction conditions and with lubricant at utilization of tester T 05. For different types of die rings (with and without ceramic coatings) the punching forces were measured during deep-drawing process. The results show that the main advantage of application of A1203 and Cr203 coatings on dies contact surfaces in comparison with dies made of tool steel may be the increase of life-time and wear resistance, the increase of the cup surface quality, savings of deficient elements by replacement of expensive tool steels by common constructional steels.

Full text (pdf)

1. Lange K.: Umformtechnik. Band 3 Blechbearbeitung, Springer-Verlag, Berlin 1990.
2. Zibulla G.G.: Auftragen des Schmierstoffes beim Tief-ziehen von Blechen, Bänder Bleche Rohre, 10/1982, 286-288.
3. Jeffery B.: Advanced lubricant technology for high-strenght steel, Stamping Journal, 2004.
4. Kim H., Altan T., Yan Q.: Evaluation of stamping lubricants in forming advanced high-strength steel (AHSS) using deep drawing and ironing test, J. Mat. Proc. Technol., 209 (2009), 4122-4133.
5. Kim H., Han S.S., Kim K., Altan T.: Evaluation of die coatings and stamping lubricants using the strip drawing test, CPF Report, CPF 2.3/08/02, 2008.
6. Trzepieciński T.: Numerical modeling of the drawbead simulator test, Zeszyty Naukowe Politechniki Rzeszowskiej, s. Mechanika, 84 (2012), 69-78.
7. Hummel S.R.: Development of a galling resistance test method with a uniform stress distribution,  Tribol. Int., 41 (2008), 175-180.
8. Swanson P.A., Ives L.K., Whitenton E.P., Peterson M.B.: A study of the galling of two steels using two test methods, Wear, 122 (1988), 207-223.
9. Vollertsen F., Zhenyu H.: Determination of size dependent friction functions in sheet metal forming with respect to the distribution of contact pressure, Prod. Eng. – Research Development, 2 (2008) 345-350.
10. Antoszewski B.: Friction and wear behavior in plasma sprayed coating, Acta Physica Polonica A, 89 (1996), 145-152.
11. Evin E., Antoszewski B.: Computer aided measu­rement and evaluation of friction ratios at deep drawing, Zeszyty Naukowe Politechniki Świętokrzyskiej, Kielce 1998.