P. Zhang
,
J.Z. Cui
,
Y.H. Du and Q.Z. Zhang(Department of Metal Forming
,
Northeastern University
,
Shenyang 110006
,
China)(Department of Mining
,
Northeastern University
,
Shenyang 110006
,
China)
金属学报(英文版)
Artificial neural networks (ANN), being a sophisticated type of information processing system by imitating the neural system of human brain, can be used to investigate the effects of concentration of flux solution, temperature of liquid aluminium, temperture of tools and pressure on thickness of the intermetallic layer at the interface between steel and aluminium under solid-liquid pressure bonding of steel and aluminium perfectly. The optimum thickness has been determined according to the value of the optimum shearing strength.
关键词:
artificial neural network
,
null
,
null
A.T.Male
,
Y.W.Chen
,
P.J.Li
,
C.Pan
,
Y.M.Zhang
材料科学技术（英文）
Plasma-jet forming is a newly proposed flexible sheet metal forming process. A non-transferred arc plasma torch is used as a controllable heat source to produce internal stress in sheet metals, causing plastic deformation without the necessity of hard tooling. This method has potential for rapid prototyping of sheet metal parts by reducing development costs and lead times. A robotic system has been used to perform simple linear bends in several different alloys. In order to develop a controllable process and to improve the forming accuracy, the effects of various process parameters on the obtained shape changes and ton the resulting structure and properties have been studied. The overall goal is to understand the roles of the forming parameters and their inter-relationship in optimizing the forming procedure-a high forming speed without damage to the material structure or properties.
关键词:
A.Cherouat
,
H.Borouchaki
材料科学技术（英文）
Ductile damage often occurs during metal forming processes due to the large thermo-elasto (visco) plastic flow localisation. This paper presents a numerical methodology, which aims to virtually improve any metal forming processes. The methodology is based on elastoplastic constitutive equations accounting for nonlinear mixed isotropic and kinematic hardening strongly coupled with isotropic ductile damage. An adaptive remeshing scheme based on geometrical and physical error estimates including a kill element procedure is used. Some numerical results are presented to show the capability of the model to predict the damage initiation and growth during the metal forming processes.
关键词:
Finite elastoplasticity
,
elastoplasticity
,
Ductile
,
damage
,
E
J.L. Song
,
D.J. Hu
,
Z.L. Chang
,
T.Y. Li
,
Z.B. Jiang
金属学报(英文版)
Based on the Finite Element Theory of Rigid Plastic, relevant problems during plastic simulation on sheet metal forming were technologically studied and simplified; a
simplified model of the blank holder during the drawing process was established and
the effects of related parameters on the forming processes were also studied. At the
same time, a finite-element numerical simulation program SPID was developed. The
distribution of strain and relationship of stress-stroke simulated were compared with
experimented, the results are well coincided with each other. It is verified that the
analytical program is reliable.
关键词:
sheet metal forming
,
null
,
null
J.H.Yang
,
J.Chen
金属学报(英文版)
Due to complexities of draw-bead restraining force calculated according to theory and depending on sheet metal forming properties experiment testing system,a simplified method to calculate draw-bead restraining force is put forward by experimental method in cup-shaped drawing process. The experimental results were compared with numerical results and proved agreement. It shows the method is efective.
关键词:
sheet metal forming
,
null
,
null
张强
,
许少普
,
李忠波
,
唐郑磊
,
高照海
,
杨阳
钢铁
doi:10.13228/j.boyuan.issn1001-0963.20150135
采用横截面为350mm×2 320 mm的钢坯轧制横截面为100 mm×2 360 mm的Q345E-Z35.在粗轧阶段以高于动态再结晶临界变形量和形状系数l/h≥0.53的条件下,经过不同的终轧温度和返红温度试验,最终确定精轧阶段终轧温度控制在780℃左右,返红温度控制在610℃左右,生产出的钢板具有优异的力学性能和层状撕裂抗性.
关键词:
Q345E-Z35
,
特厚板
,
控轧控冷
Transactions of Nonferrous Metals Society of China
The microstructure and mechanical properties of Mg-10.1Gd-3.74Y-0.25Zr (mass fraction, %) alloy (GW104 alloy) cast by metal mould casting (MMC) and lost foam casting (LFC) were evaluated, respectively. It is revealed that different forming modes do not influence the phase composition of as-cast alloy. In the as-cast specimens, the microstructures are similar and composed of alpha-Mg solid solution, eutectic compound of alpha-Mg+Mg(24)(Gd, Y)(5) and cuboid-shaped Mg(5)(Gd, Y) phase; whereas the average grain size of the alloy produced by metal mould casting is smaller than that by lost foam casting. The eutectic compound of the alloy is completely dissolved after solution treatment at 525 degrees C for 6 h, while the Mg5(Gd, Y) phase still exists after solution treatment. After peak-ageing, the lost foam cast alloy exhibits the maximum ultimate tensile strength of 285 MPa, and metal mould cast specimen 325 MPa at room temperature, while the tensile yield strengths of them are comparable. It can be concluded that GW104 alloy cast by lost foam casting possesses similar microstructure and evidently lower mechanical strength compared with metal mould cast alloy, due to slow solidification rate and proneness to form shrinkage porosities during lost foam casting process.
关键词:
Mg-Gd-Y-Zr alloy;lost foam casting;metal mould casting;microstructure;mechanical property;age-hardening response;tensile properties
Juhua HUANG
,
Jinjun RAO
,
Xuefeng LI
材料科学技术（英文）
Sheet metal forming is widely applied to automobile, aviation, space flight, ship, instrument, and appliance industries. In this paper, based on analyzing the shortcoming of general finite element analysis (FEA), the conception of parametric finite element analysis (PFEA) is presented. The parametric finite element analysis, artificial neural networks (ANN) and genetic algorithm (GA) are combined to research thoroughly on the problems of process parameters optimization of sheet metal forming. The author programs the optimization scheme and applies it in a research of optimization problem of inside square hole flanging technological parameters. The optimization result coincides well with the result of experiment. The research shows that the optimization scheme offers a good new way in die design and sheet metal forming field.
关键词:
Sheet metal forming
,
null
,
null
,
null
Journal of Materials Research
Based on the best bulk metallic glass (BMG) forming alloy in the Mg-Cu-Y ternary system, we introduced Ag (or Ni) to partially substitute for Cu to improve the glass-forming ability (GFA). The objective of this paper is twofold. First, we illustrate in detail a recently developed search strategy, which was proposed but only briefly outlined in our previous publication [H. Ma, L.L. Shi, J. Xu, Y. Li, and E. Ma: Discovering inch-diameter metallic glasses in three-dimensional composition space. Appl. Phys. Lett. 87, 181915 (2005)]. The protocol to navigate in three-dimensional composition space to land large BMGs is spelled out step-by-step using the pseudo-ternary Mg-(Cu,Ag)-Y as the model system. Second, our ability to locate the best BMG former in the composition tetrahedron allows us to systematically examine, and conclude on, the effects of a given alloying element. The large improvement in glass-forming ability in the Mg-(Cu,Ag)-Y system relative to the based ternary will be contrasted with the reduced glass-forming ability in the Mg-(Cu,Ni)-Y pseudo ternary system. It is demonstrated that the improvement of glass-forming ability requires judicious choice of substitutional alloying elements and concentrations, rather than simple additions of multiple elements assuming the "confusion principle."
关键词:
bulk metallic-glass;shaped copper mold;amorphous-alloys;thermal-stability;ternary-system;casting method;p system;diameter;zr;mm
