Wear Behaviour of Pure Ti with a Nanocrystalline Surface Layer

2011 ◽  
Vol 66-68 ◽  
pp. 1500-1504 ◽  
Author(s):  
Ming Wen ◽  
Cui'e Wen ◽  
Peter D. Hodgson ◽  
Yun Cang Li

A nanocrystalline (NC) layer with the thickness of 30 µm was produced on pure titanium surface by surface mechanical attrition treatment (SMAT). Microstructure observation indicated that the grain size increases with depth from the treated surface. The friction coefficient decreases and the wear resistance increases with the SMAT sample as compared to its coarse-grained counterpart. The improvement of the wear properties could be attributed to the higher hardness of SMAT sample.

2019 ◽  
Vol 26 (06) ◽  
pp. 1850199
Author(s):  
BAOSEN ZHANG ◽  
JIYING WANG ◽  
SHUAISHUAI ZHU ◽  
QIANGSHENG DONG ◽  
ZHANGZHONG WANG

The gradient fine-grained oxygen-boosting layer was prepared on equal channel angular processing (ECAP)-treated titanium with thermal oxidation and oxygen boost diffusion process, and tribological properties were systematically characterized. Results show that the as-prepared boosting layer consists of surface coarse-grained region, and inner fine-grained region. The corresponding thickness and mechanical properties further increase compared to those of virgin titanium. The oxygen-boosting layer reveals excellent anti-wear properties, the dominant wear mechanism of which is abrasive.


2009 ◽  
Vol 289-292 ◽  
pp. 557-563 ◽  
Author(s):  
Z.B. Wang ◽  
K. Wang ◽  
K. Lu ◽  
Gerhard Wilde ◽  
Sergiy V. Divinski

A nanostructured surface layer with a gradient microstructure was produced on a Cu plate by means of the surface mechanical attrition treatment (SMAT). Diffusion of Ni in the nanostructured layer was investigated by the radiotracer technique at temperatures from 383 to 438 K. The measured diffusion profiles consist of two distinct sections with different slopes, the steep one corresponding to the top surface layer with the grain size of 10 to 25 nm and the shallow one corresponding to a subsurface layer with a grain size of 25 to 100 nm. The effective diffusivities derived from both sections are more than 2 orders of magnitudes higher than the grain boundary diffusivities in coarse-grained Cu. The significantly accelerated diffusion rates are expected to be associated with the “non-equilibrium” states of interfaces in the nanostructured surface layer induced by SMAT. The difference between the diffusivities in the top and sub- surface layer might result from the fact that most interfaces developed from twin boundaries in the former while produced by dislocation activities in the latter.


2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Licai Fu ◽  
Jun Yang ◽  
Qinling Bi ◽  
Weimin Liu

Wear behaviour of nanocrystalline Fe88Si12alloy has been investigated in water environment compared with the coarse grained counterpart. The friction coefficient of the Fe88Si12alloy changes slightly with the grain size. The wear resistance is enhanced as the grain size decreases first and then reduces when the grain size continues to decrease, although the hardness of the Fe88Si12alloy decreases monotonically with the grain size. It is contrary to the predications of Archard’s formula. The best wear resistance of Fe88Si12alloy with grain size of 40 nm in our present work is attributed to the proper grain boundary volume fraction and composite phase structures of disordered B2 and ordered D03.


2009 ◽  
Vol 24 (10) ◽  
pp. 3136-3145 ◽  
Author(s):  
Yong Han ◽  
Lan Zhang ◽  
Jian Lu ◽  
Wengting Zhang

The thermal stability and corrosion behavior of the nanostructured layer on commercially pure zirconium, produced by surface mechanical attrition treatment (SMAT), were investigated. It is indicated that the nanograined Zr is stable at annealing temperatures up to 650 °C, above which significant grain growth occurs and the grain size shows parabolic relationship with annealing time. The activation energy for grain growth of the nanograined Zr is 59 kJ/mol at 750–850 °C, and the grain growth is dominated by grain-boundary diffusion. The as-SMATed nanograined Zr exhibits higher corrosion resistance than the 550–750 °C annealed SMATed Zr and the unSMATed coarse-grained Zr. It is indicated that the corrosion resistance of Zr tends to increase with the reduction of grain size, which is related to the dilution of segregated impurities at grain boundaries due to grain refinement and the formation of passive protection film.


2012 ◽  
Vol 463-464 ◽  
pp. 316-320 ◽  
Author(s):  
S. Anand Kumar ◽  
S. Ganesh Sundara Raman ◽  
T.S.N. Sankara Narayanan ◽  
R. Gnanamoorthy

Ti-6Al-4V alloy was subjected to surface mechanical attrition treatment (SMAT) by using SAE 52100 steel balls of 5 mm diameter for two treatment durations (30 and 60 min). SMAT resulted in the formation of nanostructured material on the surface and near surface regions, increased hardness, increased surface roughness and compressive residual stress on the surface. Treated samples exhibited lower tangential force coefficient (TFC) compared to untreated samples. Samples treated for 60 min exhibited higher grain refinement, higher hardness, lower surface roughness and higher TFC compared to the samples treated for 30 min. Fretting wear resistance of the samples treated for 30 min was higher than that of untreated samples and the samples treated for 60 min. Due to very high hardness and presumably reduced ductility, the fretting wear resistance of the samples treated for 60 min was lower than that of the untreated samples and samples treated for 30 min.


2008 ◽  
Vol 23 (1) ◽  
pp. 150-159 ◽  
Author(s):  
Y.S. Zhang ◽  
K. Wang ◽  
Z. Han ◽  
K. Lu

Nanocrystalline (NC) Cu samples were synthesized by means of surface mechanical attrition treatment, from which a layer of NC structure was formed on a coarse-grained Cu plate. Low-amplitude oscillating wear/fretting behaviors of the NC Cu samples were investigated under oil lubrication in comparison with those of as-annealed coarse-grained Cu samples. It was found the NC Cu possesses a markedly enhanced wear resistance and a higher friction coefficient relative to the coarse-grained Cu. A continuous metal transfer layer is formed on the mating ball after fretting against the NC Cu, while no material transfer occurs for the as-annealed Cu. The effects of experimental parameters and the hardness of Cu samples on the formation of a transfer layer have been systematically investigated. The transfer layer is evidenced to play an important role in the enhanced wear resistance of the NC Cu, but it has a trivial effect on its high friction coefficient.


2015 ◽  
Vol 1114 ◽  
pp. 13-21 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
Federico Gobber

Circular saw blades are used exclusively for cut-off work, ranging from small manual feed operations, up to very large power fed saws commonly used for sectioning stock as it comes from a rolling mill or other manufacturing processes for long products. The teeth profile, as well as the tooth configuration are of fundamental importance for the blade performances; through a combination of blade rigidity and grinding wheel condition a good quality surface finish is attained for tools of commercial standard. The materials used for the production of circular saw blades are ranging from high speed steel to cemented carbides. In particular, cemented carbides, being characterized by high hardness and strength, are used in applications where materials with high wear resistance and toughness are required. The main constituents of cemented carbides are tungsten carbide and cobalt. Tungsten carbide imparts the alloys the necessary strength and wear resistance, whereas cobalt contributes to the toughness and ductility of the alloys. The WC-Co alloys are tailored for specific applications by the proper choice of tungsten carbide grain size and the cobalt content. The grain size of the tungsten carbide in WC-Co varies from about 40 µm to around 0.3 µm, the cobalt content from 3 to 30 wt%. The coarse grained hardmetals are mainly used in mining applications, the smallest grain size being about 3 µm and the minimum cobalt content 6 wt%. The grain size of tungsten carbide in the metal cutting industry, as well as for universal applications lies in the range of 1-2 µm. However, with the advent of near net shape manufacturing and thin walled components, the use of submicron carbide is growing, since their high compressive strength and abrasive wear resistance can be used to produce tools with a sharp cutting edge and a large positive rake angle.In this invited paper, a general overview on the actual trends in the choice of the best material when cutting special alloys will be presented and discussed. Based on the recent and past literature some examples of their up-to-date application, such as circular saws used to cut stainless steels and some high strength alloys, are talk over.


2011 ◽  
Vol 320 ◽  
pp. 325-328 ◽  
Author(s):  
Jiang Wei Ren ◽  
Dong Li ◽  
Pei Quan Xu

A nanocrystallines surface layer was produced in Fe3Al intermetallic compound by surface mechanical attrition treatment (SMAT). The microstructure of deformed layer, phase structure and morphology of surface nanocrystallines were characterized through optical microscopy, X-ray diffractometry, transmission electronic microscopy and high resolution electronic microscopy. The results show that a deformed layer about 11μm wide is produced after 10min surface mechanical attrition. The grains on the top surface of Fe3Al are refined to nanocrystallines and the grain size of nanocrystallines is about 35nm. High density dislocations collect on the boundaries of grains. The formation of nanocrystallines is controlled by grain subdivision mechanism.


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