Features of Hot Forming Graded Composite Material and Its Experiment and Simulation

Author(s):  
Ping Hu ◽  
Ning Ma ◽  
Li-zhong Liu ◽  
Yi-Guo Zhu
2016 ◽  
Vol 716 ◽  
pp. 941-947
Author(s):  
Jun Liu ◽  
Ai Ling Wang ◽  
Hao Xiang Gao ◽  
Omer El Fakir ◽  
Xi Luan ◽  
...  

An advanced forming process involving hot forming and cold-die quenching, also known as HFQ®, has been employed to form AA6082 tailor welded blanks (TWBs). The HFQ® process combines both forming and heat treatment in a single operation, whereby upon heating the TWB, it is stamped and held between cold tools to quench the component to room temperature. The material therefore undergoes temperature, strain rate or strain path changes during the operation. In this paper, a finite element model (FEM) was developed to investigate the formability and deformation characteristics of the TWBs under HFQ® conditions. Experimental results, i.e. strain distribution, were used to compare and validate the simulation results. A good agreement between the experiment and simulation has been achieved. The developed temperature, strain rate and strain path dependent forming limit prediction model has been implemented into FE simulation to capture the complicated failure features of the HFQ® formed TWBs. It is found from both experiment and simulation that the forming speed has important effects on the occurrence of failure position, where the failure mode for the 1.5-2 mm TWBs may change from localised circumferential necking to parallel weld necking.HFQ® is a registered trademark of Impression Technologies Ltd.


2010 ◽  
Vol 156-157 ◽  
pp. 582-591 ◽  
Author(s):  
Ning Ma ◽  
Ping Hu ◽  
Zong Hua Zhang

A new type of metal composite material can be manufactured by controlling heating temperature and designing the layout of cooling pipes in hot forming process of ultra high strength steel. The yield strength of this type of metal material varies from 380 MPa to 1000 MPa continuously, and its strength limitation varies from 480 MPa to 1600 MPa continuously. In this new hot forming technology, boron steel named as 22MnB5 is stamped by one-step process of hot forming to obtain the metal composite material and manufacture the part consisting of the metal composite at the same time. The hot forming technology of U-shaped part consisting of the metal composite material is provided. Then the microstructure of the U-shaped metal composite material is analyzed and the tensile test is also implemented. The experimental results show the material properties have the characteristics of continuous distribution along the main direction of energy absorption during crash process, which indicates the feasibility of hot forming technology of the metal composite material. The top-hat thin-wall structure consisting of U-shaped metal composite material is employed to analyze the crashworthiness of the new type of metal composite material. By distributing the single phase material of U-shaped composite part properly, the energy absorption ability is increased by 58.7% and the crash force is decreased by 23.4%, which indicate the new type of metal composite material has the comprehensive performance of every single phase material. So the metal composite is a good alternative material in application of crash resistance.


Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


2019 ◽  
pp. 9-13
Author(s):  
V.Ya. Mendeleyev ◽  
V.A. Petrov ◽  
A.V. Yashin ◽  
A.I. Vangonen ◽  
O.K. Taganov

Determining the surface temperature of materials with unknown emissivity is studied. A method for determining the surface temperature using a standard sample of average spectral normal emissivity in the wavelength range of 1,65–1,80 μm and an industrially produced Metis M322 pyrometer operating in the same wavelength range. The surface temperature of studied samples of the composite material and platinum was determined experimentally from the temperature of a standard sample located on the studied surfaces. The relative error in determining the surface temperature of the studied materials, introduced by the proposed method, was calculated taking into account the temperatures of the platinum and the composite material, determined from the temperature of the standard sample located on the studied surfaces, and from the temperature of the studied surfaces in the absence of the standard sample. The relative errors thus obtained did not exceed 1,7 % for the composite material and 0,5% for the platinum at surface temperatures of about 973 K. It was also found that: the inaccuracy of a priori data on the emissivity of the standard sample in the range (–0,01; 0,01) relative to the average emissivity increases the relative error in determining the temperature of the composite material by 0,68 %, and the installation of a standard sample on the studied materials leads to temperature changes on the periphery of the surface not exceeding 0,47 % for composite material and 0,05 % for platinum.


2019 ◽  
Author(s):  
Osuke Ishida ◽  
Junichi Kitada ◽  
Katsuhiko Nunoani ◽  
Kiyoshi Uzawa

2020 ◽  
Vol 1 (12) ◽  
pp. 36-39
Author(s):  
L. V. Iyashvili ◽  
Yu. A. Vinnichenko ◽  
A. V. Vinnichenko

The purpose of the study is a quantitative assessment of the yield of dentinal fluid on the surface of the treated dentin of the tooth when restoring its structure with a composite filling material. To achieve this goal, digital images of the coronal parts of the teeth having formed carious cavities were used; virtual models of hard tissues of teeth recreated using specialized computer programs; A computer program that provides the ability to accurately determine the area of the treated dentin tooth. The results made it possible to draw the following conclusions: with an increase in the depth of the carious cavity, the amount of dentin fluid that can stand out on its surface (1–2 mm from the tooth cavity) sharply increases; with an increase in the area of the formed carious cavity (more than 30 mm2), the risk of release of a critical mass of dentinal fluid (more than 0.4 mg), which can adversely affect the strength of the adhesive interaction between the composite material and the hard tissues of the tooth, increases significantly; the same dynamics is observed with increasing time, at which there is the possibility of free exit of dentinal fluid to the surface of the cavity prepared for filling (more than 45 seconds).


2012 ◽  
Vol 2 (5) ◽  
pp. 204-205
Author(s):  
Nimesh A Patel ◽  
◽  
Pradip M Patel ◽  
Prof. A. B. Patel Prof. A. B. Patel

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