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Friction and Lubrication in Mechanical Design Episode 2 Part 11

Tham khảo tài liệu 'friction and lubrication in mechanical design episode 2 part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 480 Chapter 12 Figure 12.8 Temperature rise C in substrate interface layer and diamond layer for diamond on AIS1 304 stainless steel with a silicon nitride interface layer. U 12.7m sec 0.25 mm. Effects of Varying Parameters The effects of varying the sliding velocity of the solid u and the width of contact are examined in this section. Because the temperature rise in an uncoated substrate is inversely proportional to the square root of the sliding velocity AT oc l ựỡ it is expected that the temperature rise for the multilayered case will follow suit. Figure 12.9 illustrates this case. The parameters except for u are the same as in Fig. 12.8. As would be expected the magnitude of the temperature rise for the substrate and layers dropped with the increase in sliding velocity. The effect of increasing the width of contact is now considered. Because follows the same inverse relationships as u for the unlayered substrate AT x 1 Ự7 it is expected that the magnitude of the temperature rise will decrease. Figure 12.10 illustrates this case. The parameters except for are the same as in Fig. 12.8. As would be expected the magnitude of the temperature rise for the substrate and layers dropped with the increase in contact width. Figure 12.9 Temperature rsie C in substrate interface layer and diamond layer for diamond on AISI 304 stainless steel with a silicon nitride interface layer velocity increase with length of contact constant . U 50.8m sec 0.125 mm. Figure 12.10 Temperature rise C in substrate interface layer and diamond layer for diamond on AISI 304 stainless steel with a silicon nitride interface layer velocity constant with length of contact increase . Ư 12.7 m sec I 1.375 mm. 481 482 Chapter 12 12.8 THERMAL STRESS CONSIDERATIONS In this section simplified equations are developed for predicting the magnitude of the thermal stresses in a multilayered coating. The thermal stress in the substrate will be combined with the contact stress to determine a maximum stress .