Abstract
In order to investigate the tribological properties of alloy carbides in the die steel, a series of nanoscratching tests for chromium carbides (Cr_7C_3 carbide) containing in the cold work die steel SKD11 has been carried out using an atomic force microscope (AFM) having a two-axis force/displacement transducer. Reduced modulus of Cr_7C_3 is about 1.7 times higher than that of matrix and nanohardness of Cr_7C_3 is about 2.3 times higher than that of matrix. A reproducible groove is formed on Cr_7C_3 when the normal force exceeds 45 PN, while the minimum normal force in which the reproducible groove is formed on matrix is 15 PN. At a normal force of 100 PN, the groove formed on matrix is about 15 times deeper compared with that formed on Cr_7C_3 . When the grooves with the same depth are formed on Cr_7C_3 and matrix, a ratio of force components on Cr_7C_3 is lower than that of matrix. Thus wear characteristics of Cr_7C_3 carbide have been independently evaluated by means of the nanoscratching with AFM.
