Microstructure and nanohardness of Ag and Ni under friction in boundary lubrication

被引:13
作者
Popov, Inna [1 ]
Moshkovich, Alexey [2 ]
Cohen, Sidney R. [3 ]
Perfilyev, Vladislav [2 ]
Vakahy, Atzmon [1 ]
Rapoport, Lev [2 ]
机构
[1] Hebrew Univ Jerusalem, Ctr Nanosci & Nanotechnol, IL-91904 Jerusalem, Israel
[2] Holon Inst Technol, Dept Sci, IL-58102 Holon, Israel
[3] Weizmann Inst Sci, IL-76100 Rehovot, Israel
关键词
STACKING-FAULT ENERGY; SEVERE PLASTIC-DEFORMATION; HIGH-PRESSURE TORSION; CU-ZN ALLOYS; ULTRAFINE-GRAINED CU; MECHANICAL-PROPERTIES; STRAIN-RATE; SHEAR LOCALIZATION; SURFACE-LAYER; PURE METALS;
D O I
10.1016/j.wear.2018.03.005
中图分类号
TH [机械、仪表工业];
学科分类号
0802 ;
摘要
Microstructure Grains Dislocations Friction Wear Lubrication. Evolution of deformation microstructure and nanohardness of Ag and Ni after friction in the BL regime was studied. All friction tests were conducted under lubricated conditions using a pin-on-disk rig. Pure fee metals such as Ag and Ni, with different SFE (16 and 125 mJm(-2), respectively), were chosen as pin materials. Cross sectional transmission electron microscopy (TEM) lamellae were prepared from the pins using a focused ion beam (FIB). Using TEM, we analysed the regions of the pins that are in steady state after friction; the friction coefficient (mu) and hardness (H-s) remained unchanged with deformation in the BL regime. After the wear tests, the specimens were cross-sectioned in longitudinal and transverse directions (parallel and perpendicular to the direction of friction). Nanoindentations were performed using a Berkovich diamond tip. A gradient of grain sizes during the friction of Ag and Ni in BL regime was revealed by TEM imaging. Deformation twinning followed by limited recovery within the surface of Ag led to the formation of a relatively thick top layer of ultra-fine equiaxial grains. Thermally activated processes for the rearrangement and annihilation of dislocations are accelerated during the friction of Ni due to high SFE and contact temperature. Cross-sectional microstructures observed normal and parallel to the direction of friction are dissimilar. Steady state values of grain size, d(s), and hardness, H-s, after friction in lubricated conditions are explained by the balance between hardening and dynamic recovery in surface layers, and they strongly depend on the SFE and temperature. A correlation between the wear properties (wear coefficient) and total work of deformation during nanoindentation shows a similarity in the nano- and microscales in lubricated friction.
引用
收藏
页码:62 / 70
页数:9
相关论文
共 54 条
[1]   PLASTIC-DEFORMATION AND DAMAGE ACCUMULATION BELOW THE WORN SURFACES [J].
ALPAS, AT ;
HU, H ;
ZHANG, J .
WEAR, 1993, 162 (pt A) :188-195
[2]   Evolution of microstructural homogeneity in copper processed by high-pressure torsion [J].
An, X. H. ;
Wu, S. D. ;
Zhang, Z. F. ;
Figueiredo, R. B. ;
Gao, N. ;
Langdon, T. G. .
SCRIPTA MATERIALIA, 2010, 63 (05) :560-563
[3]   FATIGUE HARDENING IN ALLOYS OF LOW STACKING-FAULT ENERGY [J].
AVERY, DH ;
BACKOFEN, WA .
ACTA METALLURGICA, 1963, 11 (07) :653-&
[4]   STUDY ON THE EFFECT OF STACKING-FAULT ENERGY ON FATIGUE CRACK-PROPAGATION AS DEDUCED FROM DISLOCATION PATTERNS [J].
AWATANI, J ;
KATAGIRI, K ;
KOYANAGI, K .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1979, 10 (04) :503-507
[5]   Continuous dynamic recrystallization during severe plastic deformation [J].
Bacca, Mattia ;
Hayhurst, David R. ;
McMeeking, Robert M. .
MECHANICS OF MATERIALS, 2015, 90 :148-156
[6]   Influence of stacking-fault energy on microstructural characteristics of ultrafine-grain copper and copper-zinc alloys [J].
Balogh, Levente ;
Ungar, Tamas ;
Zhao, Yonghao ;
Zhu, Y. T. ;
Horita, Zenji ;
Xu, Cheng ;
Langdon, Terence G. .
ACTA MATERIALIA, 2008, 56 (04) :809-820
[7]   A study of the interactive effects of strain, strain rate and temperature in severe plastic deformation of copper [J].
Brown, Travis L. ;
Saldana, Christopher ;
Murthy, Tejas G. ;
Mann, James B. ;
Guo, Yang ;
Allard, Larry F. ;
King, Alexander H. ;
Compton, W. Dale ;
Trumble, Kevin P. ;
Chandrasekar, Srinivasan .
ACTA MATERIALIA, 2009, 57 (18) :5491-5500
[8]   Subsurface microstructure evolution and deformation mechanism of Ag-Cu eutectic alloy after dry sliding wear [J].
Cai, W. ;
Bellon, P. .
WEAR, 2013, 303 (1-2) :602-610
[9]   Microstructures and properties of copper processed by equal channel angular extrusion for 1-16 passes [J].
Dalla Torre, F ;
Lapovok, R ;
Sandlin, J ;
Thomson, PF ;
Davies, CHJ ;
Pereloma, EV .
ACTA MATERIALIA, 2004, 52 (16) :4819-4832
[10]   On the Theoretical Limits of Microstructure Evolution in Severe Plastic Deformation [J].
Diyinski, Sergiy V. ;
Padmanabhan, K. Anantha ;
Wilde, Gerhard .
NANOMATERIALS BY SEVERE PLASTIC DEFORMATION: NANOSPD5, PTS 1 AND 2, 2011, 667-669 :283-288