FABRICATION AND TRIBOLOGICAL PROPERTIES OF GRADIENT FINE-GRAINED OXYGEN-BOOSTING LAYER ON ECAP-TREATED PURE TITANIUM SURFACE

2019 ◽  
Vol 26 (06) ◽  
pp. 1850199
Author(s):  
BAOSEN ZHANG ◽  
JIYING WANG ◽  
SHUAISHUAI ZHU ◽  
QIANGSHENG DONG ◽  
ZHANGZHONG WANG
Keyword(s):  
Mechanical Properties ◽  
Diffusion Process ◽  
Tribological Properties ◽  
Wear Mechanism ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Wear Properties ◽  
Fine Grained ◽  
Equal Channel Angular Processing

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.

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
Keyword(s):  
Grain Size ◽  
Wear Resistance ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Coarse Grained ◽  
Surface Mechanical Attrition Treatment ◽  
Wear Behaviour ◽  
Wear Properties ◽  
Microstructure Observation ◽  
Mechanical Attrition

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.

Rheology of hydrocarbon gels

1950 ◽  
Vol 200 (1061) ◽  
pp. 183-188 ◽  
Keyword(s):  
Mechanical Properties ◽  
Experimental Measurement ◽  
Theoretical Basis ◽  
Continuous Media ◽  
Point Of View ◽  
Coarse Grained ◽  
Testing Instrument ◽  
Fine Grained ◽  
Mineral Oils ◽  
Space And Time

Hydrocarbon gels contain a number of materials, such as rubber, greases, saponified mineral oils, etc., of great interest for various engineering purposes. Specific requirements in mechanical properties have been met by producing gels in appropriately chosen patterns of constituent components of visible, colloidal, molecular and atomic sizes, ranging from coarse-grained aggregates, represented by sponges, foams, emulsions, etc.; to fine-grained and apparently homogeneous ones, represented by optically clear compounds. The engineer who has to deal with the whole range of such materials will adopt a macroscopic point of view, based on an apparent continuity of all the material structures and of the distributions in space and time of the displacements and forces occurring under mechanical actions. It has been possible to determine these distributions in the framework of a comprehensive scheme in which the fundamental principles of the mechanics of continuous media provide the theoretical basis, and a testing instrument of new design, termed Rheogoniometer, the means of experimental measurement (Weissenberg 1931, 1934, 1946, 1947, 1948).

scholarly journals Microstructural and Mechanical Characterization of Multilayered Iron Electrodeposits

2011 ◽  
Vol 409 ◽  
pp. 474-479 ◽  
Author(s):  
C. Chan ◽  
J.L. McCrea ◽  
G. Palumbo ◽  
Uwe Erb
Keyword(s):  
Mechanical Properties ◽  
Columnar Structure ◽  
Multilayered Structure ◽  
Structure Design ◽  
Coarse Grained ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties ◽  
Fine Grained Structure ◽  
Iron Coatings

Monolithic and multilayered iron electrodeposits were successfully synthesized by the pulse plating electrodeposition method. Electron microscopy and Vickers microhardness measurements were used to investigate the microstructure and mechanical properties of the iron electrodeposits produced. Two types of monolithic iron coatings were produced, one with a coarse grained, columnar structure and the other with an ultra-fine grained structure. Hall-Petch type grain size strengthening was observed in these monolithic coatings. Multilayered iron coatings composed of alternating layers of coarse grained and fine grained structures were also produced. The hardness value of the multilayered coatings falls between the hardness values for the two types of monolithic coatings produced. This study has demonstrated the possibility of applying a multilayered structure design to tailor the microstructure and mechanical properties of electrodeposited iron coatings.

scholarly journals Nanostructured materials based on pure titanium and bio-soluble magnesium alloy to create surgical implants

2011 ◽  
Vol 16 (4) ◽  
pp. 31-36
Author(s):  
K.V. Kutnij
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Biological Fluid ◽  
Pure Titanium ◽  
Titanium Implants ◽  
Future Application ◽  
Medical Implants ◽  
Fine Grained ◽  
Surgical Implants ◽  
Alloy We43

Influence of structural state on mechanical properties of pure titanium and magnesium alloy WE43 as candidates for use as nondegradable (titanium) and degradable (WE43) medical implants was studied. By the methods of severe plastic deformation in combination with programmed heat treatment the nanostructured pure titanium and ultra-fine-grained magnesium alloy WE43 were obtained. It is shown, that grain size substantially affects not only the mechanical properties of the indicated materials but also the corrosion rate of magnesium alloy WE43 in the medium simulating biological fluid. The possibility of replacing the titanium implants by nanostructured pure titanium and future application of degradable ultra-finegrained magnesium implants is discussed

Effects of ECAP on the Formation and Tribological Properties of Thermal Oxidation Layers on a Pure Titanium Surface

2019 ◽  
Vol 91 (3-4) ◽  
pp. 483-494 ◽  
Author(s):  
Baosen Zhang ◽  
Jiying Wang ◽  
Shuaishuai Zhu ◽  
Naishu Zhu ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Thermal Oxidation ◽  
Tribological Properties ◽  
Titanium Surface ◽  
Pure Titanium ◽  
Oxidation Layers

Effect of alloy grain size on oxidation resistance of silica-coated stainless steel

1994 ◽  
Vol 52 ◽  
pp. 676-677
Author(s):  
C. S. McDowell ◽  
S. N. Basu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Stainless Steel ◽  
Oxidation Resistance ◽  
Powder Processing ◽  
Hot Isostatic Pressing ◽  
Silica Coating ◽  
Austenitic Steels ◽  
Coarse Grained ◽  
Fine Grained

Oxidation resistance of stainless steels, which rely on the formation of a Cr2O3 (chromia) scale, can be further improved through minor alloying additions such as Al or Si, or by application of coatings to the exposed surfaces. Although, additions of Si to austenitic steels have demonstrated an improvement in oxidation resistance, high Si contents can be detrimental to the mechanical properties of these alloys. The application of a silica coating on the surface of the stainless steel provides improved oxidation resistance without detrimental effects on the mechanical properties. This study examines the effect of the grain size of the stainless steel on the effectiveness of a silica coating as an oxidation barrier.Fully austenitic stainless steel of composition Fe-18(wt%)Cr-20Ni-1.5Mn was produced in both coarsegrained and fine-grained form. The coarse-grained alloy, with a grain size of approximately 100 μm, was produced by casting and hot rolling. The fine-grained alloy, with a grain size of approximately 5 μm, was produced by rapid solidification powder processing, followed by consolidated by hot isostatic pressing and swaging.

Effect of Grain Size on Mechanical Properties of Dual Phase Steels Composed of Ferrite and Martensite

MRS Advances ◽  
2016 ◽  
Vol 1 (12) ◽  
pp. 811-816 ◽  
Author(s):  
Myeong-heom Park ◽  
Akinobu Shibata ◽  
Nobuhiro Tsuji
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Tensile Test ◽  
Coarse Grained ◽  
Dual Phase ◽  
Fine Grained ◽  
Grain Sizes ◽  
Dp Structure ◽  
Dp Steels

ABSTRACTIt is well-known that dual phase (DP) steels composed of ferrite and martensite have good ductility and plasticity as well as high strength. Due to their excellent mechanical properties, DP steels are widely used in the industrial field. The mechanical properties of DP steels strongly depend on several factors such as fraction, distribution and grain size of each phase. In this study, the grain size effect on mechanical properties of DP steels was investigated. In order to obtain DP structures with different grain sizes, intercritical heat treatment in ferrite + austenite two-phase region was carried out for ferrite-pearlite structures having coarse and fine ferrite grain sizes. These ferrite-pearlite structures with coarse and fine grains were fabricated by two types of heat treatments; austenitizing heat treatment and repetitive heat treatment. Ferrite grain sizes of the specimens heat-treated by austenitizing and repetitive heat treatment were 47.5 µm (coarse grain) and 4.5 µm (fine grain), respectively. The ferrite grain sizes in the final DP structures fabricated from the coarse-grained and fine-grained ferrite-pearlite structures were 58.3 µm and 4.1µm, respectively. The mechanical behavior of the DP structures with different grain sizes was evaluated by an uniaxial tensile test at room temperature. The local strain distribution in the specimens during tensile test was obtained by a digital image correlation (DIC) technique. Results of the tensile test showed that the fine-grained DP structure had higher strength and larger elongation than the coarse-grained DP structure. It was found by the DIC analysis that the fine-grained DP structure showed homogeneous deformation compared with the coarse-grained DP structure.

Harmonic Structure Design of Co-Cr-Mo Alloy with Outstanding Mechanical Properties

2014 ◽  
Vol 939 ◽  
pp. 60-67 ◽  
Author(s):  
Choncharoen Sawangrat ◽  
Osamu Yamaguchi ◽  
Sanjay Kumar Vajpai ◽  
Kei Ameyama
Keyword(s):  
Mechanical Properties ◽  
Mechanical Milling ◽  
Three Dimensional ◽  
High Strength ◽  
Surface Region ◽  
Structure Design ◽  
Coarse Grained ◽  
Harmonic Structure ◽  
Fine Grained ◽  
Plasma Sintering

Co-Cr-Mo alloy powders were subjected to controlled mechanical milling at room temperature under Ar atmosphere to fabricate bimodal microstructure in the MM powders, having nanosized grains in the surface region and micron-sized coarse grains in the center of the milled powders. Subsequently, the MM powder was compacted by spark-plasma sintering (SPS) process. The sintered compacts indicated two structure areas: (i) ultra-fine grained (UFG) regions, called shell, and (ii) the coarse grained regions called core. The shell and the core correspond to the surface and center of the MM powders, respectively. The shell regions established a continuous three dimensional network of high strength ultra-fine grained regions, which surrounded the discrete coarse grained ductile regions. Such a microstructure is referred as Harmonic Structure. The sintered Co-Cr-Mo alloy compacts exhibited outstanding mechanical properties. The yield strength increased from 605 to 635 MPa, and ultimate tensile strength increased from 1201 to 1283 MPa. Moreover, the elongation was maintained more or less same as that of coarse grained compacts. Therefore, the harmonic structure design leads to the new generation microstructure of Co-Cr-Mo alloy, which demonstrates outstanding mechanical properties, i.e. superior strength and excellent ductility as compared to conventional materials. Keywords: mechanical milling, Co-Cr-Mo alloys, mechanical properties, harmonic structure.

scholarly journals Effects of Multi-Axial Compression on the Mechanical and Fretting Wear Properties of Ti-45Nb Alloys

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 454
Author(s):  
Zhuoqing Xu ◽  
Nan Hu ◽  
Yuan Lu ◽  
Xiaochang Xu
Keyword(s):  
Axial Compression ◽  
Wear Mechanism ◽  
Adhesive Wear ◽  
Stress Shielding ◽  
Fretting Wear ◽  
Shielding Effect ◽  
Oxidative Wear ◽  
Wear Properties ◽  
Fine Grained ◽  
Grain Sizes

Biocompatible β-type Ti-45Nb alloy with a low elastic modulus is promising in alleviating the stress shielding effect of Ti-based hard-tissue replacement implants. In this work, the ultra-fine-grained (UFG) microstructures with different grain sizes were prepared by multi-axial compression (MAC) processing of Ti-45Nb alloys, and the mechanical properties and the fretting wear properties of Ti-45Nb alloys in different grain sizes were investigated. The results show that the yield strength and ultimate tensile strength of the sample processed by 27 passes MAC increase by 76% and 91%, respectively, with an elongation of more than 9%. After MAC processing, the friction coefficient and volume wear rate gradually decrease. In addition, before MAC processing, the Ti-45Nb sample shows a wear mechanism of severe adhesive wear, oxidative wear and fatigue delamination; while after MAC processing, the wear mechanism switches to abrasive wear and slight adhesive wear with slight oxidative wear, indicating that grain refinement helps to improve the anti-fretting properties of Ti-45Nb alloys.

scholarly journals Effect of ion nitriding by glow discharge on the physical and mechanical properties of the plastically deformed tool steel R6M5

2021 ◽  
Vol 2064 (1) ◽  
pp. 012052
Author(s):  
R K Vafin ◽  
A V Asylbaev ◽  
D V Mamontov ◽  
I D Sklizkov ◽  
G I Raab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glow Discharge ◽  
Tool Steel ◽  
Physical And Mechanical Properties ◽  
Coarse Grained ◽  
Steel R6m5 ◽  
Ion Nitriding ◽  
Fine Grained ◽  
Fine Grained Structure

Abstract This work is devoted to the study of the effect of the duration of ion nitriding by glow discharge on the physical and mechanical properties of tool steel with different initial structure. We used specimens of R6M5 tool steel with a coarse-grained structure obtained after annealing at a temperature of 850°C and with a fine-grained structure obtained after severe plastic deformation by torsion discharge. With an increase in the duration of ion nitriding, the thickness of the hardened layer and wear resistance increase. The combination of plastic deformation with ion nitriding by glow discharge increases the adsorption and diffusion rate of the saturating element due to the creation of a highly fragmented and disoriented fine-grained structure and contributed to reduction in processing time.

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