scholarly journals Numerical and Experimental Study on the Hot Cross Wedge Rolling of Ti-6Al-4V Vehicle Lower Arm Preform

2021 ◽  
Author(s):  
Peiai Li ◽  
Baoyu Wang ◽  
Pengni Feng ◽  
Jinxia Shen ◽  
Jiapeng Wang
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Geometric Dimension ◽  
Radial Force ◽  
Phase Region ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Initial State ◽  
Forming Quality ◽  
Tc4 Alloy

Abstract Cross wedge rolling (CWR) has unique advantages in the production of shaft preforms with refined grains and improved mechanical properties. Considering the sensitivity of Ti-6Al-4V (TC4) alloy to heat treatment temperature, the effect of different initial deformation temperatures (IDTs) on the forming quality, mechanical properties and microstructure evolution of the TC4 alloy lower arm preforms in CWR forming were studied in this work. The flow stress curves of TC4 alloy in the two-phase region were obtained by isothermal compression experiments. The Arrhenius constitutive model was established and applied to DEFORM-3D finite element (FE) software to simulate the CWR forming process of TC4 alloy lower arm preforms. The forming quality of TC4 alloy parts was compared and analyzed by 3D FE simulation and experiment. And their mechanical properties at room temperature were tested by tensile test. The results showed that the rolled part has well forming quality (no steps and necking defects) and higher geometric dimension accuracy at the IDT 850°C. Moreover, with the increase of IDT, the radial force and torque in the rolling process decrease. In addition, there were no internal defects in the parts rolled by different IDTs, because the die gap reduces the number of alternating cycles of tensile-compressive stress in the rolled workpieces. Compared with the initial state, the microstructure was refined. When the IDT is 885 °C, the ultimate tensile strength (UTS), yield strength (YS) and elongation (EI) of the parts were 987 MPa, 924 MPa and 16.8 % respectively, which was able to ensure the mechanical performance requirements of the lower arm preform. The results provide theoretical guidance for the actual production of lower arm preform by CWR.

Application of Support Vector Machine to Predicting Mechanical Properties of TC4

2011 ◽  
Vol 189-193 ◽  
pp. 1854-1857 ◽  
Author(s):  
Zhe Zhe Hou ◽  
Yan Liang Du ◽  
Wei Gang Zhao ◽  
Meng Zhao ◽  
Shuang Chao Peng
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Support Vector Machine ◽  
Mechanical Performance ◽  
Heating Temperature ◽  
Heating Time ◽  
Experimental Results ◽  
Support Vector ◽  
Machine Method ◽  
Tc4 Alloy

On the basis of numerous experimental results the effect of heat treatment on mechanical properties of TC4 alloy is studied. A computer model expressing the relationships between heat treatment and mechanical properties has been established with supported vector machine method. The input parameters were determined by the heating temperature and heating time which are important factors of the mechanical performance, and the output parameters are tensile and yield strength and elongation. The model is established by libsvm with RBF kernel function, e-SVR and proper parameters. Experimental results show that prediction accuracy made by using support vector machine reached over 95%, and the model has good learning precision and generalization and it can be used for predicting the mechanical properties of TC4 alloy.

Effect of different lapping orders on mechanical performance and nugget forming process for three-sheet dissimilar resistance spot welding joints between DC06 and unequal-thickness hot-stamped B1500HS steel sheets

2021 ◽  
Vol 118 (1) ◽  
pp. 112
Author(s):  
Xin Mao ◽  
Zhi Cheng ◽  
Qiang Zhu ◽  
Wurong Wang ◽  
Xicheng Wei ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Formation Mechanism ◽  
Mechanical Performance ◽  
Peak Load ◽  
Element Model ◽  
Type I ◽  
Type Ii ◽  
Forming Process ◽  
Pull Out ◽  
Nugget Formation

In this study, the mechanical properties of two welded joints under different lapping orders (B1500HS-1.4 mm/B1500HS-1.6 mm/DC06, denoted as type I; B1500HS-1.4 mm/DC06/B1500HS-1.6 mm, denoted type II) were compared. The nugget formation mechanism was analysed by a coupled electrical-thermal finite element model (FEM). It is found that different lapping orders significantly affect the mechanical properties of three-sheet RSW joints. All RSW joints tend to fail in the pull-out or tearing failure mode. The peak load of the two interfaces of type II RSW joint is more balanced, and the failure load of which is much higher than that of the type I RSW joint; The warpage was observed at type I welded joint. Considered the load-carrying capacity, type II was excellent. The simulation results indicate that the diameter of the weld nugget at the upper interface of the type I RSW joint was larger than that on the other interfaces, which agree well with the experimental results. The nugget formation mechanism of dissimilar high strength steel three-sheet RSW joint was obtained that forming the nugget firstly from two interfaces and final formed nuggets were asymmetric.

Effect of rolling parameters on forming quality of flat cross wedge rolling thread shafts

2020 ◽  
pp. 095440892095259 ◽  
Author(s):  
YiYu Shao ◽  
WenFei Peng ◽  
Xuan Yu ◽  
Moliar Oleksandr ◽  
Vyacheslav Titov
Keyword(s):  
Axial Force ◽  
Element Model ◽  
Helix Angle ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Forming Quality ◽  
Rolling Parameter ◽  
The Right ◽  
Forming Angle

The flat cross wedge rolling is an advanced forming process, which is used to produce thread shafts. In this work, a finite element model of flat cross wedge rolling thread shafts was established by the DEFORM-3D, and the effect of the forming angle, spreading angle, helix angle and flank angle on forming quality are investigated. The research results show that the forming angle, spreading angle, helix angle have a significant influence on the position of the die wedge-in point. The angle designed wrongly makes the die wedge-in point unable to be aligned correctly, causing defects such as slipping in the process, repeated rolling of formed thread, thin or incomplete tooth shapes. The flank angle mainly makes an impact on the axial force. Reducing the right flank angle or increasing the left flank angle can effectively improve the imbalance of axial force to obtain high-quality thread shafts. Through the experiment of flat cross wedge rolling thread shafts, the data comparison demonstrates that the error of the external dimension of formed parts is small, proving the reliability of the rolling parameter selection.

Deformation Behavior of Hollow Axles With Constant Hole Diameter by Three-Roll Skew Rolling

2020 ◽  
Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Jitai Wang ◽  
Chang Xu
Keyword(s):  
Mechanical Properties ◽  
Rolling Direction ◽  
Rolling Process ◽  
Hole Diameter ◽  
Stress And Strain ◽  
Forming Process ◽  
Processing Efficiency ◽  
Forming Quality ◽  
Material Utilization ◽  
Skew Rolling

Abstract At present, hollow axles with constant hole diameter is mainly formed by turning thick-walled hollow tubes. This method of processing has low material utilization and processing efficiency. And heat treatment is required to improve the mechanical properties of hollow axles. To improve the material utilization and processing efficiency of hollow axles with constant hole diameter during the forming process, a new processing technique, three-roll skew rolling process, is proposed to form a hollow axles with constant hole diameter in this paper. The three-roll skew rolling process is a continuous plastic forming process, which has high material utilization and processing efficiency, and it can improve the mechanical properties of the rolled parts. Firstly, combining the working principle of three-roll skew rolling and the structural characteristics of hollow axles with constant hole diameter, the forming mechanism of hollow axles with constant hole diameter by three-roll skew rolling is described. Secondly, the finite element model of the hollow axles with constant hole diameter by three-roll skew rolling is established according to the dimensions of the hollow axles with constant hole diameter, the material characteristics of the hollow axles, and the stable rolling conditions of three-roll skew rolling. The process parameters of the hollow axles are also determined. Thirdly, according to each step position of the hollow axles, the forming process of the hollow axles with constant hole diameter by three-roll skew rolling is divided into 5 deformation stages. Lastly, the stress and strain field of each deformation stage of the hollow axles was analyzed. The results show that the dimensions of the hollow axles with constant hole diameter by three-roll skew rolling are very close to the designed dimensions, which indicates that the material utilization of the rolled hollow axles is very high. Along the rolling direction, the descending step of the hollow axle is easier to form than the ascending step, and the forming quality is also better. The surface metal of the rolled hollow axles flows faster than the internal metal. Areas with large stress and strain are mainly concentrated at both ends of the rolled hollow axles. And the magnitude of stress and strain gradually decrease from the surface to the center. The hollow axles with constant hole diameter by three-roll skew rolling has a good forming quality and high forming efficiency. The hollow axles with constant hole diameter is formed by three-roll skew rolling process, which has broad application prospects.

scholarly journals Investigation of the Mechanical Properties and Microstructure of Nickel Superalloys Processed in Shear Forming / Identyfikacja Właściwości Mechanicznych Oraz Mikrostruktury Superstopów Niklu Przetwarzanych W Procesie Kształtowania Obrotowego

2015 ◽  
Vol 60 (4) ◽  
pp. 2637-2644 ◽  
Author(s):  
K. Żaba ◽  
M. Nowosielski ◽  
S. Puchlerska ◽  
M. Kwiatkowski ◽  
P. Kita ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Laser Heating ◽  
Basic Research ◽  
Nickel Superalloy ◽  
Nickel Superalloys ◽  
Forming Process ◽  
Initial State ◽  
Plastic Properties ◽  
X Ray ◽  
Microstructure Of The Material

The paper presents the research results of the mechanical properties and microstructure of the material in initial state and parts made from nickel superalloy Inconel®718 in the rotary forming process with laser heating. In the first step was carried out basic research of chemical composition, mechanical properties, hardness and microstructure of sheet in initial state. Then from the metal sheet, in industrial conditions, was made axisymmetric parts in the flow and shear forming with laser heating. Parts were subjected to detailed studies focused on the analysis of changes in the mechanical properties and microstructure in the relation to the material in initial state. The analysis was based on the tests results of strength and plastic properties, hardness, microstructural observations and X-ray microanalysis in the areas where defects appear and beyond. The results are presented in the form of tables, charts, and photographs of the microstructure.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

Weldability - Behavior of Welded Reinforcement

2019 ◽  
Vol 70 (10) ◽  
pp. 3469-3472
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Mechanical Characteristics ◽  
Mechanical Performance ◽  
Current Work ◽  
Carbon Equivalent ◽  
Work Process ◽  
Ultimate Limit

Weldability involves two aspects: welding behavior of components and safety in operation. The two aspects will be reduced to the mechanical characteristics of the elements and to the chemical composition. In the case of steel reinforcing rebar’s, it is reduces to the percentage of Cech(carbon equivalent) and to the mechanical characteristics: the yielding limit, the ultimate limit, and the elongations which after that represent the ductility class in which the re-bars is framed. The paper will present some types of steel reinforcing rebar’s with its mechanical characteristics and the welding behavior of those elements. In the current work, process-related behavior of welded reinforcement, joint local and global mechanical properties, and their correlation with behavior of normal reinforcement and also the mechanical performance resulted in this type of joints. Keywords: welding behavior, ultimate limit, reinforcing rebar’s

scholarly journals Preparation of Long Sisal Fiber-Reinforced Polylactic Acid Biocomposites with Highly Improved Mechanical Performance

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1124
Author(s):  
Zhifang Liang ◽  
Hongwu Wu ◽  
Ruipu Liu ◽  
Caiquan Wu
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Mechanical Performance ◽  
Tensile Elongation ◽  
Sisal Fiber ◽  
Fiber Reinforced ◽  
Impact Performance ◽  
The Matrix ◽  
Blending Process ◽  
Extension Direction

Green biodegradable plastics have come into focus as an alternative to restricted plastic products. In this paper, continuous long sisal fiber (SF)/polylactic acid (PLA) premixes were prepared by an extrusion-rolling blending process, and then unidirectional continuous long sisal fiber-reinforced PLA composites (LSFCs) were prepared by compression molding to explore the effect of long fiber on the mechanical properties of sisal fiber-reinforced composites. As a comparison, random short sisal fiber-reinforced PLA composites (SSFCs) were prepared by open milling and molding. The experimental results show that continuous long sisal fiber/PLA premixes could be successfully obtained from this pre-blending process. It was found that the presence of long sisal fibers could greatly improve the tensile strength of LSFC material along the fiber extension direction and slightly increase its tensile elongation. Continuous long fibers in LSFCs could greatly participate in supporting the load applied to the composite material. However, when comparing the mechanical properties of the two composite materials, the poor compatibility between the fiber and the matrix made fiber’s reinforcement effect not well reflected in SSFCs. Similarly, the flexural performance and impact performance of LSFCs had been improved considerably versus SSFCs.

scholarly journals Tribological and Mechanical Properties of Multicomponent CrVTiNbZr(N) Coatings

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 41
Author(s):  
Yin-Yu Chang ◽  
Cheng-Hsi Chung
Keyword(s):  
Mechanical Properties ◽  
Nitrogen Content ◽  
Adhesion Strength ◽  
Mechanical Performance ◽  
Bulk Material ◽  
High Entropy Alloy ◽  
Composition Gradient ◽  
Multilayered Structures ◽  
High Entropy ◽  
Alloy Target

Multi-element material coating systems have received much attention for improving the mechanical performance in industry. However, they are still focused on ternary systems and seldom beyond quaternary ones. High entropy alloy (HEA) bulk material and thin films are systems that are each comprised of at least five principal metal elements in equally matched proportions, and some of them are found possessing much higher strength than traditional alloys. In this study, CrVTiNbZr high entropy alloy and nitrogen contained CrVTiNbZr(N) nitride coatings were synthesized using high ionization cathodic-arc deposition. A chromium-vanadium alloy target, a titanium-niobium alloy target and a pure zirconium target were used for the deposition. By controlling the nitrogen content and cathode current, the CrNbTiVZr(N) coating with gradient or multilayered composition control possessed different microstructures and mechanical properties. The effect of the nitrogen content on the chemical composition, microstructure and mechanical properties of the CrVTiNbZr(N) coatings was investigated. Compact columnar microstructure was obtained for the synthesized CrVTiNbZr(N) coatings. The CrVTiNbZrN coating (HEAN-N165), which was deposited with nitrogen flow rate of 165 standard cubic centimeters per minute (sccm), exhibited slightly blurred columnar and multilayered structures containing CrVN, TiNbN and ZrN. The design of multilayered CrVTiNbZrN coatings showed good adhesion strength. Improvement of adhesion strength was obtained with composition-gradient interlayers. The CrVTiNbZrN coating with nitrogen content higher than 50 at.% possessed the highest hardness (25.2 GPa) and the resistance to plastic deformation H3/E*2 (0.2 GPa) value, and therefore the lowest wear rate was obtained because of high abrasion wear resistance.

Experimental investigation of the mechanical behavior of glass fiber/high fluidity polyamide-based composites for automotive market

2021 ◽  
pp. 073168442110140
Author(s):  
Hossein Ramezani-Dana ◽  
Moussa Gomina ◽  
Joël Bréard ◽  
Gilles Orange
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
Mechanical Performance ◽  
Physical And Mechanical Properties ◽  
Ultimate Strain ◽  
Uniaxial Tensile ◽  
Compression Tests ◽  
Automotive Market ◽  
Glass Fiber Reinforced ◽  
Glass Fiber Reinforcement

In this work, we examine the relationships between the microstructure and the mechanical properties of glass fiber–reinforced polyamide 6,6 composite materials ( V f = 54%). These materials made by thermocompression incorporate different grades of high fluidity polyamide-based polymers and two types of quasi-UD glass fiber reinforcement. One is a classic commercial fabric, while the other specially designed and manufactured incorporates weaker tex glass yarns (the spacer) to increase the planar permeability of the preform. The effects of the viscosity of the polymers and their composition on the wettability of the reinforcements were analyzed by scanning electron microscopy observations of the microstructure. The respective influences of the polymers and the spacer on the mechanical performance were determined by uniaxial tensile and compression tests in the directions parallel and transverse to the warp yarns. Not only does the spacer enhance permeability but it also improves physical and mechanical properties: tensile longitudinal Young’s modulus increased from 38.2 GPa to 42.9 GPa (13% growth), tensile strength increased from 618.9 MPa to 697 MPa (3% growth), and decrease in ultimate strain from 1.8% to 1.7% (5% reduction). The correlation of these results with the damage observed post mortem confirms those acquired from analyses of the microstructure of composites and the rheological behaviors of polymers.

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