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Online since: February 2015
Authors: Xiu Lan Li, Xin Jun Zhou, You Ping Ma, Wen Ling Xie
Introduction
Bimetallic composite material has been extensively employed as an advanced functional material in many fields because it has attractive mechanical properties.
During composite casting, interfacial bonding between matrix metal and liquid metal is the major factors determining corresponding mechanical properties of the composite material.
Heat diffusion rate was an important factor that influenced carbides size.
[10] Avcı A, İlkaya N, Şimşir M, Mechanical and microstructural properties of low-carbon steel-plate reinforced gray cast iron, J.
[14] Lu L, Soda H, McLean A, Microstructure and mechanical properties of Fe-Cr-C eutectic composites, Mater.
During composite casting, interfacial bonding between matrix metal and liquid metal is the major factors determining corresponding mechanical properties of the composite material.
Heat diffusion rate was an important factor that influenced carbides size.
[10] Avcı A, İlkaya N, Şimşir M, Mechanical and microstructural properties of low-carbon steel-plate reinforced gray cast iron, J.
[14] Lu L, Soda H, McLean A, Microstructure and mechanical properties of Fe-Cr-C eutectic composites, Mater.
Online since: July 2015
Authors: Yan Xu, Jian Pin Zhou, Zheng Ying Wei, Li Yan Dang, Feng Lin Wu
Clinical bone tissue engineering includes several elements: seed cells, scaffolds material and growth factors, etc.
Then, we analyzed its macroscopic, microscopic structure and mechanical properties, it showed good quality.
Mechanical Property of Bone Scaffold Bone scaffold requires a certain mechanical strength to provide support for the new organization, to maintain the space environment of cell growth, to maintain a certain period until the new organization has its own biomechanical property.
The structure conformed with the request of biomechanical properties of the bone repair.
[7] Dagang Guo, Xu for prototyping template structure and properties of modulation-doped strontium biphasic calcium phosphate ceramic bone scaffold [J].
Then, we analyzed its macroscopic, microscopic structure and mechanical properties, it showed good quality.
Mechanical Property of Bone Scaffold Bone scaffold requires a certain mechanical strength to provide support for the new organization, to maintain the space environment of cell growth, to maintain a certain period until the new organization has its own biomechanical property.
The structure conformed with the request of biomechanical properties of the bone repair.
[7] Dagang Guo, Xu for prototyping template structure and properties of modulation-doped strontium biphasic calcium phosphate ceramic bone scaffold [J].
Online since: May 2021
Authors: Alexey D. Zhukov, I.I. Popov, S.P. Chernukhin, M.O. Asamatdinov
The properties of plaster mixes and plaster coatings depend on many factors.
The dependence of the properties of the plastering mixtures was carried out in the process of using the three-factor experiment.
The experimental conditions, factors, their average set values, and ranges of variation are given in Table 1.
The strength of the clay-gypsum binder in compression (Y3) is an optimization characteristic of its properties.
Discussion Equation analysis shows that, in determination areas of variable factors established by the experimental conditions (Table 1), the setting time is most affected by the consumption of plasticizer and, to a less extent, the consumption of Portland cement (coefficients at X1 and X2).
The dependence of the properties of the plastering mixtures was carried out in the process of using the three-factor experiment.
The experimental conditions, factors, their average set values, and ranges of variation are given in Table 1.
The strength of the clay-gypsum binder in compression (Y3) is an optimization characteristic of its properties.
Discussion Equation analysis shows that, in determination areas of variable factors established by the experimental conditions (Table 1), the setting time is most affected by the consumption of plasticizer and, to a less extent, the consumption of Portland cement (coefficients at X1 and X2).
Online since: July 2008
Authors: Shi Qi Cui, Jin Shan Wang, Zhao Zhen Pei, Zhi Liu
Introduction
The rehabilitation or strengthening of reinforced concrete can increase bearing capacity and lessen
the deflection when the bearing capacity and deflection of the concrete beam are insufficient which
can be due to any of the following factors including: incorrect selection of materials, errors in design
calculations and detailing, poor construction methods and inadequate quality control and supervision,
chemical attack, and external physical or mechanical factors.
Material properties of CFRP laminates used to strengthen concrete beams are indicated in Table 2.
Material properties of CFRP laminates Theoretical thickness (mm) Elasticity modulus (GPa) Tensional strength (MPa) 0.111 220 3750 Prestressed CFRP Pressure distribtion beam Deflection gauges Deflection gauges Deflection gauges Hydraulic jack Reaction force Fig. 1 Measure scheme of test Figure 2 shows the device used for the application of prestress to the CFRP laminates.
Comparison of structure capacity by specimen Specimen Initial cracking load (kN) Failure load (kN) Spacing of cracks (mm) Modes of failure L1 16.5 64.7 135 Steel yielding L2 17.6 80.1 112 Concrete crushing L3 26.1 85.6 80 Concrete crushing Fig. 3 Comparison of the crack of the L2 and L3 beam (the left is the crack of L2 ) One of the important factors that affect the serviceability of a RC flexural member is its deflection.
Material properties of CFRP laminates used to strengthen concrete beams are indicated in Table 2.
Material properties of CFRP laminates Theoretical thickness (mm) Elasticity modulus (GPa) Tensional strength (MPa) 0.111 220 3750 Prestressed CFRP Pressure distribtion beam Deflection gauges Deflection gauges Deflection gauges Hydraulic jack Reaction force Fig. 1 Measure scheme of test Figure 2 shows the device used for the application of prestress to the CFRP laminates.
Comparison of structure capacity by specimen Specimen Initial cracking load (kN) Failure load (kN) Spacing of cracks (mm) Modes of failure L1 16.5 64.7 135 Steel yielding L2 17.6 80.1 112 Concrete crushing L3 26.1 85.6 80 Concrete crushing Fig. 3 Comparison of the crack of the L2 and L3 beam (the left is the crack of L2 ) One of the important factors that affect the serviceability of a RC flexural member is its deflection.
Online since: January 2010
Authors: Robert D. Caligiuri, Lawrence E. Eiselstein, L.N. Eastep
Three essential factors must coincide for HAC (or more specifically SSCC) to occur in socket
welds:
1.
Material in a susceptible condition (microstructure produced by thermal mechanical processing history, i.e., high hardness in the weld or heat-affected zone (HAZ) due to un-tempered martensite).
However, in any specific situation or application, the relative importance of each of these factors will differ.
In the case of socket welds, it is primarily the properties of the HAZ and exposed root weld metal that will affect material susceptibility to SSCC since these regions of the weld will have the highest strength and more susceptible microstructure.
Effects of the Socket Welding Process Proper design of the socket welding process takes into account many factors, including the geometry of the joint.
Material in a susceptible condition (microstructure produced by thermal mechanical processing history, i.e., high hardness in the weld or heat-affected zone (HAZ) due to un-tempered martensite).
However, in any specific situation or application, the relative importance of each of these factors will differ.
In the case of socket welds, it is primarily the properties of the HAZ and exposed root weld metal that will affect material susceptibility to SSCC since these regions of the weld will have the highest strength and more susceptible microstructure.
Effects of the Socket Welding Process Proper design of the socket welding process takes into account many factors, including the geometry of the joint.
Online since: August 2017
Authors: Jens Gibmeier, Robert Mücke, Robert Vaßen, Markus Mutter, Hyoung C. Back
However, a mechanical layer removal will affect the local residual stress distribution.
Finally, it must be mentioned that the actual residual stress distribution in thermally sprayed coatings has been recognized as one of the important key factors for fatigue and failure behavior of the layered component [10].
Table 1: Chemical composition and properties of substrate material Chemical composition (wt. %) Elements Fe Cr Mn Si Ti Al Ni La Co Crofer 22 APU Bal. 22.2 0.46 0.03 0.06 0.02 0.02 0.07 - The substrates were grit blasted prior to plasma spraying to improve the adhesion (mechanical anchoring) of the coating [12].
The mechanical properties of the coatings and the substrate are listed in table 2.
Table 2: Mechanical properties of coatings and substrate material Elastic modulus [GPa] Poisson’s ratio Coefficient of thermal expansion [K-1] Mn1.0Co1.9Fe0.1O4 96* 0.36* 12.3 x 10-6[3] Crofer 22 APU 210 0.28 11.9 x 10-6[4] * : Measurement by means of ultrasonic spectroscopy The combinations of MCF coating thicknesses and Crofer substrate thicknesses, which are investigated in the present project, are listed in table 3.
Finally, it must be mentioned that the actual residual stress distribution in thermally sprayed coatings has been recognized as one of the important key factors for fatigue and failure behavior of the layered component [10].
Table 1: Chemical composition and properties of substrate material Chemical composition (wt. %) Elements Fe Cr Mn Si Ti Al Ni La Co Crofer 22 APU Bal. 22.2 0.46 0.03 0.06 0.02 0.02 0.07 - The substrates were grit blasted prior to plasma spraying to improve the adhesion (mechanical anchoring) of the coating [12].
The mechanical properties of the coatings and the substrate are listed in table 2.
Table 2: Mechanical properties of coatings and substrate material Elastic modulus [GPa] Poisson’s ratio Coefficient of thermal expansion [K-1] Mn1.0Co1.9Fe0.1O4 96* 0.36* 12.3 x 10-6[3] Crofer 22 APU 210 0.28 11.9 x 10-6[4] * : Measurement by means of ultrasonic spectroscopy The combinations of MCF coating thicknesses and Crofer substrate thicknesses, which are investigated in the present project, are listed in table 3.
Online since: October 2011
Authors: Xue Wen Chen, Qi Zhang
DRX plays a key role in reducing the flow stress and the grain size and is a powerful tool for controlling mechanical properties during industrial processing [4].
In recent years, the influence factors for critical strain and the critical strain model have been widespread concerned [5].
The aim of this paper is to study the key factors which influence the grain size and the microstructure evolution during Cr4 steel hot deformation process by thermo-simulation experiments, and to determine the critical strain model which can provide basic data for designers to develop the hot forging process technique parameters of heavy supporting roller and control the microstructure of this product.
This machine can be programmed to simulate both the thermal and the mechanical industrial process variables for a wide range of hot deformation conditions.
During the hot forming process, the critical strain () is mainly affected by the temperature and strain rate, but also affected by the original grain size and hot deformation activation energy.
In recent years, the influence factors for critical strain and the critical strain model have been widespread concerned [5].
The aim of this paper is to study the key factors which influence the grain size and the microstructure evolution during Cr4 steel hot deformation process by thermo-simulation experiments, and to determine the critical strain model which can provide basic data for designers to develop the hot forging process technique parameters of heavy supporting roller and control the microstructure of this product.
This machine can be programmed to simulate both the thermal and the mechanical industrial process variables for a wide range of hot deformation conditions.
During the hot forming process, the critical strain () is mainly affected by the temperature and strain rate, but also affected by the original grain size and hot deformation activation energy.
Online since: April 2011
Authors: Fritz Klocke, Barbara Linke, Anh Tuan Vu, Michael Duscha
The objectives of the following study are to improve the temperature simulation based on Finite Element Methods (FEM) by connecting multi-influenced factors within the model with the input parameters.
(5) Factor bw includes the workpiece material properties, thermal conductivity kw, specific heat capacity cw and density ρw.
In this research, a material model with temperature dependent material properties was implemented which avoided the limitation brought by assuming constant thermal properties in analytical approaches.
The heat flux reflects the contact load within the grinding zone, and is originated from the tangential load as shown in equation (1), but presented approaches above did not include these factors to derive the heat source profile.
The shown difference in the maximum temperature position helps researchers understand the duration of temperature affecting the surface contrasting between different heat profiles.
(5) Factor bw includes the workpiece material properties, thermal conductivity kw, specific heat capacity cw and density ρw.
In this research, a material model with temperature dependent material properties was implemented which avoided the limitation brought by assuming constant thermal properties in analytical approaches.
The heat flux reflects the contact load within the grinding zone, and is originated from the tangential load as shown in equation (1), but presented approaches above did not include these factors to derive the heat source profile.
The shown difference in the maximum temperature position helps researchers understand the duration of temperature affecting the surface contrasting between different heat profiles.
Online since: October 2012
Authors: Yong Lin Kang, Fan Zhang, Nan Nan Song, Jun Zhang, Qiang Zhu
Compared with conventional liquid die casting process, rheo-diecasting process had unique advantages in reducing the internal defects and improving mechanical properties of castings.
During the filling process, there were two factors which affected the filling behavior of the fluid together with each other.
This reflects not only the pseudoplastic behavior of fluids under high shear rate, but also the Newtonian behavior under low shear rate, which is more in line with the rheological properties of semi-solid alloy slurry.
Meanwhile, the small solidification shrinkage in rheo-diecasting also helps to reduce or eliminate the defects of the casting shrinkage loose, and thus has unique advantages to improve mechanical properties of castings due to reduction of internal defects.
Kool, Properties of semisolid aluminum matrix composites, Mater.
During the filling process, there were two factors which affected the filling behavior of the fluid together with each other.
This reflects not only the pseudoplastic behavior of fluids under high shear rate, but also the Newtonian behavior under low shear rate, which is more in line with the rheological properties of semi-solid alloy slurry.
Meanwhile, the small solidification shrinkage in rheo-diecasting also helps to reduce or eliminate the defects of the casting shrinkage loose, and thus has unique advantages to improve mechanical properties of castings due to reduction of internal defects.
Kool, Properties of semisolid aluminum matrix composites, Mater.
Online since: May 2014
Authors: Yong Gan, Han Chao Wang
Consequently, what other factors affect the TWBs’ forming ability, how they work on the sheet forming, and what quantitative relationship between the TWBs’ formability and the influence factors are deserved questions on research.
In the finite element simulation, the tools(punch, die and blank holder) were modeled as rigid materials, the difference of material thickness is reflected in the blank holders, the blank holders were split in two parts, the distance between two parts was half of the TWBs’ thickness, a circler draw bead was provided on the blank holder of 132.6mm diameter to restrict the flow of metal, Square sheet metal was regarded as a plastic material, and the size is 180 mm 180 mm, belytschko-tsay thin shell elements were applied for the blank and tools to reduce the calculate time, using the adaptive grid in the mesh, on the both sides of parent sheet were meshed under the different layer, which is ignoring the material properties of heat affected zone, the finite element model and the corresponding boundary conditions in the Dome test were shown in Fig. 2 and Table 1.
When two sides of the parent sheet have the same thickness, the weld-line doesn’t move, due to the two sides of parent sheet has the same property, the TWBs deformed uniform.
Formability Principles of linear-weld-line tailor-weld blanks(TWBs) with different thickness ratios, Chinese Journal of Mechanical Engineering, Vol 44(5) (2008), p. 215-219
Weld-bead movement and formability of tailor-welded blanks during forming automobile panels, Chinese Journal of Mechanical Engineering, Vol 40(9) (2004), p. 62-66
In the finite element simulation, the tools(punch, die and blank holder) were modeled as rigid materials, the difference of material thickness is reflected in the blank holders, the blank holders were split in two parts, the distance between two parts was half of the TWBs’ thickness, a circler draw bead was provided on the blank holder of 132.6mm diameter to restrict the flow of metal, Square sheet metal was regarded as a plastic material, and the size is 180 mm 180 mm, belytschko-tsay thin shell elements were applied for the blank and tools to reduce the calculate time, using the adaptive grid in the mesh, on the both sides of parent sheet were meshed under the different layer, which is ignoring the material properties of heat affected zone, the finite element model and the corresponding boundary conditions in the Dome test were shown in Fig. 2 and Table 1.
When two sides of the parent sheet have the same thickness, the weld-line doesn’t move, due to the two sides of parent sheet has the same property, the TWBs deformed uniform.
Formability Principles of linear-weld-line tailor-weld blanks(TWBs) with different thickness ratios, Chinese Journal of Mechanical Engineering, Vol 44(5) (2008), p. 215-219
Weld-bead movement and formability of tailor-welded blanks during forming automobile panels, Chinese Journal of Mechanical Engineering, Vol 40(9) (2004), p. 62-66