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QUANTITATIVE ANALYTIC TECHNOLOGY OF ULTRA-HARDNESS AND WEAR RESISTENT SURFACING MATERIAL
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作者 W.S.Li B.S.Wang +2 位作者 L.Z.Feng Y.Q.Zhou Y.M.Zhang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第1期28-32,共5页
Mathematical models between surfacing welding properties of C, Cr, Mo, V, W alloy system and encode factors of alloy additives are established by test methods of advanced trial optimizing technology and computer assis... Mathematical models between surfacing welding properties of C, Cr, Mo, V, W alloy system and encode factors of alloy additives are established by test methods of advanced trial optimizing technology and computer assistant design (CAD). They help to draw unitary functions and binary isoclines diagrams through which the influence of encode factorial linearity, nonlinear effect and factors interaction of alloy additives on the performances of surfacing welding can be analyzed directly and quantitatively. Meanwhile, the performances of deposited metal can also be predicted according to the content of alloy additives. 展开更多
关键词 surfacing materials ultra-high hardness wear resistant quantitative analysis
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Correlation between hardness and SEM-EDS characterization of palm oil waste based biocoke
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作者 Asri Gani Erdiwansyah +5 位作者 Hera Desvita Saisa Mahidin Rizalman Mamat Zulhaini Sartika Ratna Eko Sarjono 《Energy Geoscience》 EI 2024年第4期253-266,共14页
This research investigates the relationship between hardness and microstructure obtained through SEM-EDS analysis of palm oil waste-based biocoke.The mechanical qualities and chemical composition of biocoke are being ... This research investigates the relationship between hardness and microstructure obtained through SEM-EDS analysis of palm oil waste-based biocoke.The mechanical qualities and chemical composition of biocoke are being studied concerning the influence of temperature conditions.The manufacturing temperature of biocoke may vary between 150℃ and 190℃.Utilizing SEM-EDS,we were able to characterize the microstructure and analyze the elemental composition,while the Hardness Shore D approach was used for the most complex materials.These results highlight the possibility of optimizing production temperature to produce biocoke with better mechanical performance.They show a positive correlation between biocoke hardness and structured carbon content.At 150℃ and 180℃,respectively,the EFB biocoke reached its maximum hardness level of 62±5.At 190℃,OPM biocoke generated a 60±5 times greater hardness than that of OPM and OPF biocoke.The OPT biocoke sample had the highest porosity with a score of 0.86,or 85.76%.Furthermore,compared to EFB biocoke,OPM and OPF biocokes had a priority of 0.84(84.20%)and 0.83(83.48%),respectively.Biocoke hardness is a quality indicator of physical and chemical qualities;the vital link between biocoke hardness,structural features,and elemental composition supports this idea. 展开更多
关键词 Biocoke Palm oil waste hardness SEM-EDS Processing temperature
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Gravel hardness effect on compaction characteristics of gravelly soil
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作者 SHI Yunfang LI Shengang +1 位作者 JIANG Chen LIU Jinning 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1432-1443,共12页
The compaction characteristics of gravelly soil are affected by gravel hardness.To investigate the evolution and influencing mechanism of different gravel hardness on the compaction characteristics of gravelly soil,he... The compaction characteristics of gravelly soil are affected by gravel hardness.To investigate the evolution and influencing mechanism of different gravel hardness on the compaction characteristics of gravelly soil,heavy compaction tests and crushing tests were conducted on gravelly soils with gravels originated from hard,soft and extremely soft rocks.According to orthogonal experiments and variance analysis,it was found that hardness has a significant impact on the maximum dry density of gravelly soil,followed by gravel content,and lastly,moisture content.For gravel compositions with an average saturated uniaxial compressive strength less than 60 MPa,the order of compacted maximum dry density is soft gravels>hard gravels>extremely soft gravels.Each type of gravelly soil has a threshold for gravel content,with 60%for hard and soft gravels and 50%for extremely soft gravels.Beyond these thresholds,the compacted dry density decreases significantly.There is a certain interaction between hardness,gravel content,and moisture content.Higher hardness increases the influence of gravel content,whereas lower hardness increases the influence of moisture content.Gravelly soils with the coarse aggregate(CA)between 0.7 and 0.8 typically achieve higher dry densities after compaction.In addition,the prediction equations for the particle breakage rate and CA ratio in the Bailey method were proposed to estimate the compaction performance of gravelly soil preliminarily.The results further revealed the compaction mechanism of different gravelly soils and can provide reference for subgrade filling construction. 展开更多
关键词 Gravelly soil hardness Compaction characteristics Crushing characteristics Particle breakage rate Bailey method
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Influence of heat input on microhardness and microstructure across the welding interface between stainless steel and low alloy steel
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作者 ZHU Min 《Baosteel Technical Research》 CAS 2024年第1期14-21,共8页
The welding interface is crucial to the service safety of dissimilar metal weld(DMW)joints between stainless steel(SS)and low alloy(LA)steel.Different status of welding interfaces was prepared by cladding SS consumabl... The welding interface is crucial to the service safety of dissimilar metal weld(DMW)joints between stainless steel(SS)and low alloy(LA)steel.Different status of welding interfaces was prepared by cladding SS consumables to LA steel substrates with different heat inputs via tungsten inert gas arc welding(TIG),followed by a series of microstructural characterizations and hardness tests.Results showed that a hardening and transition layer(TL)would be generated along the welding interface,and the width and hardening degree of the TL would increase with the heat input.Meanwhile,heavy load hardness tests showed that highly severe inhomogeneous plastic deformation and the microcrack would be generated in the interfacial region and the welding interface respectively in the highest heat input sample(1.03 kJ/mm).These results indicate that the increase in heat input would deteriorate the bonding performance of DMW joints.Further microstructural observations showed that the higher hardening degree of the highest heat input sample was mainly attributed to the stronger grain boundary,solution,and dislocation strengthening effects. 展开更多
关键词 welding interface transition layer heat input MICROSTRUCTURE hardness
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Friction welding influence on microstructure,microhardness and hardness behavior of CrNiMo steel(AISI 316)
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作者 Ammar Jabbar Hassan Billel Cheniti +3 位作者 Brahim Belkessa Taoufik Boukharouba Djamel Miroud Nacer-Eddine Titouche 《China Welding》 CAS 2023年第3期21-27,共7页
For joining high Cr,Ni and Mo austenitic stainless steel(AISI 316)by direct drive friction welding(DDFW),with friction weld-ing conditions:rotation speed of 3000 r/min,friction time of 10 s,friction pressure of 130 MP... For joining high Cr,Ni and Mo austenitic stainless steel(AISI 316)by direct drive friction welding(DDFW),with friction weld-ing conditions:rotation speed of 3000 r/min,friction time of 10 s,friction pressure of 130 MPa,forge time of 5 s and forge pressure of 260 MPa.The results of microstructure showed that the temperature at the interface reached 819℃while forge applied between 357-237℃,which subdivided welded joint into four distinct regions of highly plastically deformed zone(HPDZ),thermo-mechanically affected zone(TMAZ),heat affected zone(HAZ)and the base metal,with grain size about 10µm,100µm,90µm and 30µm respectively.These re-gions were created due to dynamic recrystallization(DRX)at the interface and thermo-mechanical deformation with heat diffusion in the neighboring regions.Whereas,high level of microhardness about 300 HV0.1 and hardness roughly 240 Hv10 at the interface due to HPDZ creation while low level of 240 HV0.1 for microhardness and moderately of 205 HV10 for hardness in neighboring regions. 展开更多
关键词 friction welding austenitic stainless steel MICROSTRUCTURE MICROhardness hardness
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Relationship between Hardness and Deformation during Cold Rolling Process of Complex Profles 被引量:1
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作者 Dawei Zhang Linghao Hu +1 位作者 Bingkun Liu Shengdun Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第5期315-329,共15页
The hardening on surface of complex profles such as thread and spline manufactured by cold rolling can efectively improve the mechanical properties and surface quality of rolled parts. The distribution of hardness in ... The hardening on surface of complex profles such as thread and spline manufactured by cold rolling can efectively improve the mechanical properties and surface quality of rolled parts. The distribution of hardness in superfcial layer is closely related to the deformation by rolling. To establish the suitable correlation model for describing the relationship between strain and hardness during cold rolling forming process of complex profles is helpful to the optimization of rolling parameters and improvement of rolling process. In this study, a physical analog experiment refecting the uneven deformation during complex-profle rolling process has been extracted and designed, and then the large date set (more than 400 data points) of training samples refecting the local deformation characteristics of complexprofle rolling have been obtained. Several types of polynomials and power functions were adopted in regression analysis, and the regression correlation models of 45# steel were evaluated by the single-pass and multi-pass physical analog experiments and the complex-profle rolling experiment. The results indicated that the predicting accuracy of polynomial regression model is better in the strain range (i.e., ε < 1.2) of training samples, and the correlation relationship between strain and hardness out strain range (i.e., ε > 1.2) of training samples can be well described by power regression model;so the correlation relationship between strain and hardness during complex-profle rolling process of 45# steel can be characterized by a segmented function such as third-order polynomial in the range ε < 1.2 and power function with a ftting constant in the range ε > 1.2;and the predicting error of the regression model by segmented function is less than 10%. 展开更多
关键词 Complex profle Cold rolling Multi passes Equivalent strain Vickers hardness
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Dietary protein levels changed the hardness of muscle by acting on muscle fiber growth and the metabolism of collagen in sub-adult grass carp(Ctenopharyngodon idella) 被引量:1
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作者 Min Dong Lu Zhang +8 位作者 Pei Wu Lin Feng Weidan Jiang Yang Liu Shengyao Kuang Shuwei Li Haifeng Mi Ling Tang Xiaoqiu Zhou 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第2期729-744,共16页
Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is ex... Background:Nutrient regulation has been proven to be an effective way to improve the flesh quality in fish.As a necessary nutrient for fish growth,protein accounts for the highest proportion in the fish diet and is expensive.Although our team found that the effect of protein on the muscle hardness of grass carp was probably related to an increased collagen content,the mechanism for this effect has not been deeply explored.Moreover,few studies have explored the protein requirements of sub-adult grass crap(Ctenopharyngodon idella).Therefore,the effects of different dietary protein levels on the growth performance,nutritional value,muscle hardness,muscle fiber growth,collagen metabolism and related molecule expression in grass carp were investigated.Methods:A total of 450 healthy grass carp(721.16±1.98 g)were selected and assigned randomly to six experimen-tal groups with three replicates each(n=25/replicate),and were fed six diets with 15.91%,19.39%,22.10%,25.59%,28.53%and 31.42%protein for 60 d.Results:Appropriate levels of dietary protein increased the feed intake,percentage weight gain,specific growth rate,body composition,unsaturated fatty acid content in muscle,partial free amino acid content in muscle,and muscle hardness of grass carp.These protein levels also increased the muscle fiber density,the frequency of new muscle fibers,the contents of collagen and IGF-1,and the enzyme activities of prolyl 4-hydroxylases and lysyloxidase,and decreased the activity of matrix metalloproteinase-2.At the molecular level,the optimal dietary protein increased col-lagen type Iα1(Colα1),Colα2,PI3K,Akt,S6K1,La ribonucleoprotein domain family member 6a(LARP6a),TGF-β1,Smad2,Smad4,Smad3,tissue inhibitor of metalloproteinase-2,MyoD,Myf5,MyoG and MyHC relative mRNA levels.The levels of the myostatin-1 and myostatin-2 genes were downregulated,and the protein expression levels of p-Smad2,Smad2,Smad4,p-Akt,Akt,LARP6 and Smad3 were increased.Conclusions:The appropriate levels of dietary protein promoted the growth of sub-adult grass carp and improved muscle hardness by promoting the growth of muscle fibers,improving collagen synthesis and depressing collagen degradation.In addition,the dietary protein requirements of sub-adult grass carp were 26.21%and 24.85%according to the quadratic regression analysis of growth performance(SGR)and the muscle hardness(collagen content),respectively. 展开更多
关键词 Collagen degradation Collagen synthesis Grass carp Muscle fibers Muscle hardness PROTEIN
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Influence of quenching medium on the dendrite morphology,hardness,and tribological behaviour of cast Cu-Ni-Sn spinodal alloy for defence application 被引量:1
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作者 Bipin Sankar Karthik V Shankar +4 位作者 Vamu Sunil Hemanth Kashyap S Nikhil Nair Adarsh A.Nair Abhinav P M 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第12期83-100,共18页
Cu-Ni-Sn spinodal alloys(Spinodal bronze)are potential materials with robust applications in components associated with defence applications like bearings,propellers,bushes,and shafts of heavily loaded aircraft,off-ro... Cu-Ni-Sn spinodal alloys(Spinodal bronze)are potential materials with robust applications in components associated with defence applications like bearings,propellers,bushes,and shafts of heavily loaded aircraft,off-road vehicles,and warships.This paper presents a comparative study using water,Brine solution,and SAE 40 oil as the quenching media in regular bronze(Cu-6Sn)and spinodal bronze(Cu-9Ni-6Sn)alloys.Morphological analysis was conducted by optical microscopy,transmission electron microscopy(TEM),and X-ray diffraction technique(XRD)on bronze and spinodal bronze samples immersed in the three different quenching media to understand the grain size and hardness values better.Tribological analysis was performed to analyze the effect of quenching media on the wear aspects of bronze and spinodal bronze samples.The hardness value of the brine-aged spinodal bronze samples was as high as 320 Hv,and the grain size was very low in the range of 60μm.A quantitative comparison between brine-aged regular bronze and brine-aged spinodal bronze showed that the hardness(Hv)was almost 80%higher for brine-aged spinodal bronze.Further,the grain size was approximately 30%finer for spinodal bronze when compared with regular bronze.When the load was increased in spinodal bronze samples,there was an initial dip in wear rate followed by a marginal increase.There was a steady increase in friction coefficient with a rise in load for brine-aged regular bronze and spinodal bronze samples.These results indicate that brine solution is the most effective quenching medium for cast Cu-Ni-Sn spinodal alloys. 展开更多
关键词 Quenching Water BRINE SAE 40 oil Grain size hardness Wear rate Spinodal decomposition CuSn Spinodal alloy CuNiSn
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Effect of Dynamic Strain Aging on Hardness in the Heat-Affected Zone of SUS316 Steel Welds
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作者 Lina Yu Kazutoshi Nishimoto Kazuyoshi Saida 《材料科学与工程(中英文A版)》 2023年第1期13-25,共13页
DSA(dynamic strain aging)phenomenon in SUS316 steel was investigated using isothermal and non-isothermal tensile tests of simulated HAZ(heat-affected zone)thermal cycles.Isothermal tensile tests were performed on SUS3... DSA(dynamic strain aging)phenomenon in SUS316 steel was investigated using isothermal and non-isothermal tensile tests of simulated HAZ(heat-affected zone)thermal cycles.Isothermal tensile tests were performed on SUS316 in the peak temperature range of 20-700°C,with strain rates varying from 4.2×10^(-3)to 4.2×10^(-5)s^(-1).Based on the appearance of discontinuous plastic flows,expressed as serrations,and the hardening phenomenon of the tensile samples,the conditions for the occurrence of DSA in the SUS316 steel were investigated.Furthermore,the extent of hardening due to DSA was evaluated by comparing the hardness values of the SUS316 and SUS316EHP steels after the tensile tests.To confirm the effect of DSA on hardness in the HAZ of the welded SUS316 steel,non-isothermal tensile tests of the simulated HAZ thermal cycles were performed using a Thermec Master.The relationship between the increase in Vickers hardness due to DSA and the strain in the HAZ was determined;the effect of DSA on hardness in the HAZ could be predicted.The DSA in SUS316 steel was found to be mainly attributed to the dynamic interaction of dislocations with C and N interstitial atoms during high-temperature deformation. 展开更多
关键词 Dynamic strain aging hardness SERRATION heat-affected zone SUS316
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Optimize Multiple Peening Effects on Surface Integrity and Microhardness of Aluminum Alloy Induced by LSP
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作者 Enoch Asuako Larson Samuel Adu-Gyamfi +7 位作者 Milku Augustine Philip Yamba Jamal-Deen Kukurah Karimu Abdulai Joseph Sekyi-Ansah Osman Abdul-Razak Emmanuel A. Akurugu Aston Kuzmin 《Materials Sciences and Applications》 2023年第3期208-221,共14页
Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current stu... Laser shock peening is a modernized surface enhancement performed methodically to improve fatigue life, enhance the hardness of the material and make coarse grains flat under the superficial layer. In this current study, the effect of varying optimized multiple laser shock peening (LSP) is studied on the surface integrity, microhardness, and mechanical properties. The results show that the LSP-treated specimens have visible signs of valleys, wavy and varying height distribution as well as dimples. However, the presence of non-uniformity and sharp protrusions was detected from the superficiality of the as-received specimen and this was so because of the SiC abrasive material used to polish the superficial layer of the specimen before the test experiment. Prior to LSP, the surface roughness was 2 μm, however, after LSP the roughness increased to 4 μm, 6 μm and 17 μm for 1, 2, and 4 impacts, respectively. High-density dislocation can also be observed close to the grain boundary because the grain boundary prevents the migration of dislocation which could lead to dislocation walls and dislocation tangles. The increase in impacts decrease the average grain size, nevertheless, the micro-strain increased after multiple impacts. Furthermore, coarse grains after LSP were transformed into finer grains. The increase in the number of impacts increases the micro-strain likewise the full-width half maximum (FWHM). Finally, the increase in microhardness increases as the LSP impacts increase. 展开更多
关键词 Surface Integrity MICROhardness Sharp Protrusions SiC Abrasive Material FWHM
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Effects of cubic carbides and La additions on WC grain morphology,hardness and toughness of WC-Co alloys 被引量:9
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作者 张立 陈述 +3 位作者 程鑫 吴厚平 马鋆 熊湘君 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1680-1685,共6页
Effects of Cr3C2,VC and La2O3 additions on the WC grain morphology,hardness and toughness of WC-10Co alloys were investigated.To intensify the grain growth driving force,nano W and nano C,instead of the conventionally... Effects of Cr3C2,VC and La2O3 additions on the WC grain morphology,hardness and toughness of WC-10Co alloys were investigated.To intensify the grain growth driving force,nano W and nano C,instead of the conventionally used WC,were used as the starting materials.To obtain a three-dimensional WC grain morphology,the natural sinter skins of the alloys were observed directly by scanning electron microscopy.It is shown that the additions have a strong ability in regulating the WC grain morphological and grain size distribution characteristics and the combinations of hardness and toughness.Due to the formation of regular and homogeneous triangular platelet WC grains,WC-10Co-0.6Cr3C2-0.06La2O3 alloy shows an excellent combination of hardness and toughness.The morphological regulation mechanism,the relationship between the WC grain morphology and the properties were discussed. 展开更多
关键词 cemented carbide rare earth grain growth platelet WC grain hardness TOUGHNESS
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Effect of welding heat input and post-welded heat treatment on hardness of stir zone for friction stir-welded 2024-T3 aluminum alloy 被引量:3
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作者 陈雨 丁桦 +3 位作者 李继忠 赵敬伟 付明杰 李晓华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第8期2524-2532,共9页
The microstructure and hardness of the stir zone (SZ) with different welding heat inputs were investigated for friction stir-welded 2024-T3 aluminum by transmission electron microscopy, differential scanning calorim... The microstructure and hardness of the stir zone (SZ) with different welding heat inputs were investigated for friction stir-welded 2024-T3 aluminum by transmission electron microscopy, differential scanning calorimeter and Vickers micro-hardness test. The results show that welding heat input has a significant effect on the hardness of the SZ. Under high welding heat input condition, a higher welding speed is beneficial for improving the hardness of the SZ. However, when the welding heat input is low, the hardness of the SZ elevates with increasing the rotation speed. The hardness of the SZ decreases after post-welded heat treatment due to overaging. The joints welded at 500 r/min and 100 mm/min show a high resistance to overaging. The reduction of hardness in the SZ is only 3.8%, while in other joints, the reduction is more than 10%. The morphology of strengthening precipitates plays important roles for the improvement of hardness. 展开更多
关键词 aluminum alloy friction stir welding heat treatment heat input hardness
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Interfacial behaviors of epoxy asphalt surfacing on steel decks 被引量:6
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作者 陈先华 黄卫 钱振东 《Journal of Southeast University(English Edition)》 EI CAS 2007年第4期594-598,共5页
A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the ep... A model for predicting the interface behavior of epoxy asphalt and steel composite beam under negative bending is developed incorporating partial interaction theory. Interfacial slips between the steel deck and the epoxy asphalt surfacing are included in the model with a new parameter of membrane stiffness. A series of analytical equations based on this model are derived to calculate slip and strain at the interface. Also, a numerical procedure for calculating the load responses of simply supported composite beams with concentrated force at the mid-span is established and verified with two samples. Characters of slip and strain at the interface, sensitivities of tensile stress and interface shear stress with material parameters are studied. It can be concluded that interfacial effects decrease the bending stiffness of the composite; hard and stiff bonding material is better for asphalt surfacing layer working at normal to low temperatures, and the damage of the asphalt surfacing layer will be accelerated with the damage accumulation of the bonding coat. 展开更多
关键词 epoxy asphalt surfacing steel bridge deck interfacial behavior composite beam
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Influence of Floating Body Effect on Radiation Hardness of PD SOI nMOSFETs
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作者 赵洪辰 海潮和 +1 位作者 韩郑生 钱鹤 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2005年第2期234-237,共4页
H-gate and closed-gate PD SOI nMOSFETs are fabricated on SIMOX substrate,and the influence of floating body effect on the radiation hardness is studied.All the subthreshold characteristics of the devices do not change... H-gate and closed-gate PD SOI nMOSFETs are fabricated on SIMOX substrate,and the influence of floating body effect on the radiation hardness is studied.All the subthreshold characteristics of the devices do not change much after radiation of the total dose of 106rad(Si).The back gate threshold voltage shift of closed-gate is about 33% less than that of H-gate device.The reason should be that the body potential of the closed-gate device is raised due to impact ionization,and an electric field is produced across the BOX.The floating body effect can improve the radiation hardness of the back gate transistor. 展开更多
关键词 floating body effect radiation hardness SOI
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HARDNESS PROPERTY AND WEAR RESISTANCE OF Al_2O_(3P)/ Zn-Al COMPOSITE
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作者 陶杰 崔益华 +3 位作者 肖军 冯健 邹香甫 李顺林 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1995年第2期155-160,共6页
The hardness values and the wear resistance of Al2O3P/ Zn-Al composite, prepared by means of rheological casting technology,are investigated separately in this work. The results show that the addition of Al2O3P increa... The hardness values and the wear resistance of Al2O3P/ Zn-Al composite, prepared by means of rheological casting technology,are investigated separately in this work. The results show that the addition of Al2O3P increases the hardness values of the matrix at both room and high temperature and improves the wear resistance of the material.The hardness values and the wear resistance of the composite rise with the increase of the particle volume fraction or the decrease of the particle size.The raising of test temperature results in a rapid descending of its hardness values.However, the addition of Al2O3P improves the property of high temperature resistance of Zn-Al alloys significantly.Moreover,the effect of quenching, tempering or cycling heat treatment on the hardness values of the composite is also studied. 展开更多
关键词 metallic matrix composites zinc alloys wear resistance Al_2O_(3P) particles hardness value
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On the Indeterminacy in Hardness of Shape Memory Alloys
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作者 F.T.Cheng 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2004年第6期700-702,共3页
The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al. The origin of the indeterminacy is attributed to the inadequacy of the con... The present communication addresses an interesting problem related to the indeterminacy in hardness of superelastic NiTi reported by Xu et al. The origin of the indeterminacy is attributed to the inadequacy of the conventional Vickers hardness testing measurement which does not record elastic deformation, and thus the indeterminacy may be removed with suitable techniques. Concepts of hardness in relation to deformation are clarified. Recommendations for measuring the hardness of NiTi and other elastic-plastic materials are suggested, together with comments on the advantages and disadvantages of each of these methods. 展开更多
关键词 hardness Elastic-plastic materials Elastic recovery Vickers microhardness test NITI SMA
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Conversion between Vickers hardness and nanohardness by correcting projected area with sink-in and pile-up effects
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作者 Youping LU Yue SU +4 位作者 Wei GE Tengfei YANG Zhanfeng YAN Yugang WANG Songqin XIA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第6期188-199,共12页
The Vickers hardness test has been widely used for neutron-irradiated materials and nanoindentation for ion-irradiated materials.Comparing the Vickers hardness and nanohardness of the same materials quantitatively and... The Vickers hardness test has been widely used for neutron-irradiated materials and nanoindentation for ion-irradiated materials.Comparing the Vickers hardness and nanohardness of the same materials quantitatively and establishing a correlation between them is meaningful.In this study,five representative materials—pure titanium(Ti),nickel(Ni),tungsten(W),304 coarse-grained stainless steel(CG-SS)and 304 nanocrystalline austenitic stainless steel(NG-SS)—are investigated for comparison.The results show that the relationship between Vickers hardness and nanohardness does not conform to a mathematical geometric relationship because of sink-in and pile-up effects confirmed by finite element analysis(FEA)and the results of optical microscopy.Finally,one new method was developed by excluding the effects of sink-in and pile-up in materials.With this improved correction in the projected area of the Vickers hardness and nanohardness,the two kinds of hardness become identical. 展开更多
关键词 Vickers hardness nanohardness CONVERSION
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Effect of indentation size and grain/sub-grain size on microhardness of high purity tungsten 被引量:2
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作者 刘光玉 倪颂 宋旼 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第10期3240-3246,共7页
Hardness of materials depends significantly on the indentation size and grain/sub-grain size via microindentation and nanoindentation tests of high-purity tungsten with different structures.The grain boundary effect a... Hardness of materials depends significantly on the indentation size and grain/sub-grain size via microindentation and nanoindentation tests of high-purity tungsten with different structures.The grain boundary effect and indentation size effect were explored.The indentation hardness was fitted using the Nix-Gao model by considering the scaling factor.The results show that the scaling factor is barely correlated with the grain/sub-grain size.The interaction between the plastically deformed zone(PDZ) boundary and the grain/sub-grain boundary is believed to be the reason that leads to an increase of the measured hardness at the specific depths.Results also indicate that the area of the PDZ is barely correlated with the grain/sub-grain size,and the indentation hardness starts to stabilize once the PDZ expands to the dimension of an individual grain/sub-grain. 展开更多
关键词 high purity tungsten indentation hardness indentation size effect grain boundary plastic deformation zone
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Resin-Surfacing复合型树脂碎石在润扬大桥钢桥面的运用
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作者 梅建峰 马韩灵 《黑龙江交通科技》 2016年第7期107-108,共2页
我国当前正处于大跨径桥梁建设的高峰期,同时面临大跨径钢桥面铺装养护期,如何提高桥面铺装管养水平,关系到钢桥面铺装的使用寿命。依据对润扬大桥钢桥面早期出现的裂缝等病害采用ResinSurfacing复合型树脂碎石的工艺,对在实际操作及取... 我国当前正处于大跨径桥梁建设的高峰期,同时面临大跨径钢桥面铺装养护期,如何提高桥面铺装管养水平,关系到钢桥面铺装的使用寿命。依据对润扬大桥钢桥面早期出现的裂缝等病害采用ResinSurfacing复合型树脂碎石的工艺,对在实际操作及取得的经验做具体的介绍,以期对类似钢桥面环氧早期养护带来一定参考。 展开更多
关键词 Resin—surfacing复合型树脂碎石 环氧裂缝处理 封层 日常养护
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In situ synthesis and hardness of TiC/Ti_5Si_3 composites on Ti-5Al-2.5Sn substrates by gas tungsten arc welding 被引量:5
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作者 Wen-qing Yan Le Dai Chi-bin Gui 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2013年第3期284-289,共6页
TiC/TisSi3 composites were fabricated on Ti-5A1-2.5Sn substrates by gas tungsten arc welding (GTAW). Identification of the phases was performed using X-ray diffraction (XRD). The microstructures were analyzed usin... TiC/TisSi3 composites were fabricated on Ti-5A1-2.5Sn substrates by gas tungsten arc welding (GTAW). Identification of the phases was performed using X-ray diffraction (XRD). The microstructures were analyzed using scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDS) and optical microscopy (OM). The Vickers hardness was measured with a micro-hardness tester. The TiC/TisSi3 composites were obtained in a double-layer track, and the Vickers hardness of the track increased by two to three times compared with the Ti-5A1-2.5Sn substrate. 展开更多
关键词 titanium alloys surface modification gas tungsten arc welding (GTAW) microstructure hardness
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