Korean Journal of Materials Research, Vol.23, No.7, 392-398, July, 2013
2-pass 이주속압연된 인탈산동판재의 두께방향으로의 미세조직 및 기계적 특성
Microstructure and Mechanical Property in Thickness Direction of a Deoxidized Low-Phosphorous Copper Sheet Processed by Two-Pass Differential Speed Rolling
A two-pass differential speed rolling(DSR) was applied to a deoxidized low-phosphorous copper alloy sheet in order to form a homogeneous microstructure. Copper alloy with a thickness of 3 mm was rolled to 75 % reduction by two-pass rolling at 150 oC without lubrication at a differential speed ratio of 2.0:1. In order to introduce uniform shear strain into the copper alloy sheet, the second rolling was performed after turning the sample by 180o on the transverse direction axis. Conventional rolling(CR), in which the rotating speeds of the upper roll and lower roll are identical to each other, was also performed by two-pass rolling under a total rolling reduction of 75 %, for comparison. The shear strain introduced by the conventional rolling showed positive values at positions of the upper roll side and negative values at positions of the lower roll side. However,
samples processed by the DSR showed zero or positive values at all positions. {100}//ND texture was primarily developed near the surface and center of thickness for the CR, while {110}//ND texture was primarily developed for the DSR. The difference in misorientation distribution of grain boundary between the upper roll side surface and center regions was very small in the CR, while it was large in the DSR. The grain size was smallest in the upper roll side region for both the CR and the DSR. The hardness showed homogeneous distribution in the thickness direction in both CR and DSR. The average hardness was larger in CR than in DSR.
Keywords:differential speed rolling;copper alloy;microstructure;electron backscatter diffraction(EBSD);strain
- Lua DP, Wang J, Zengb WJ, Liu Y, Lub L, Suna BD, Mater. Sci. Eng., A421, 254 (2006)
- Kim YG, Hwang BC, Lee SH, Lee CW, Shin DH, J. Kor. Inst. Met. & Mater., 46(9), 545 (2008)
- Sakai T, Hamada S, Saito Y, Scripta Mater., 44, 2569 (2001)
- Kim KH, Lee DN, Acta Mater., 49, 2583 (2001)
- Lee SH, Lee DN, J. Mech. Sci., 43, 1997 (2001)
- Lee SH, Sakai T, Shin DH, Mater. Trans., 44(7), 1382 (2003)
- Watanabe J, Sakai T, Iwamoto N, Utsunomiya H, J. Japan Research Institute for Advanced Cu-Base Materials and Technologies, 44(1), 73 (2005)
- Kim WJ, Park JD, Kim WY, J. ALLOYS and COMPOUNDS, 460, 289 (2008)
- Lee SH, Yoon DJ, Sakai T, Kim SH, Han SZ, J. Kor. Inst. Met. & Mater., 47(2), 121 (2009)
- Lee SH, Yoon DJ, Euh KJ, Kim SH, Han SZ, J. Kor. Inst. Met. & Mater., 48(1), 77 (2010)
- Lee SH, Lim JY, Utsunomiya H, Euh KJ, Han SZ, J. Kor. Inst. Met. & Mater., 48(10), 942 (2010)
- Lee SH, Korean J. Mater. Res., 22(11), 581 (2012)