Effect of the metal base structure on the impact ductility of malleable and high-tensile cast irons

1988 ◽  
Vol 30 (4) ◽  
pp. 276-277
Author(s):  
V. I. Ovchinnikov ◽  
N. A. Umerenkova ◽  
V. A. Sharkov
1984 ◽  
Vol 26 (7) ◽  
pp. 500-502
Author(s):  
S. A. Yurasov ◽  
L. Ya. Kozlov ◽  
E. V. Rozhkova ◽  
O. M. Romanov ◽  
L. M. Romanov
Keyword(s):  

2020 ◽  
Vol 184 ◽  
pp. 01033 ◽  
Author(s):  
K. Sunil Kumar Reddy ◽  
M. Kannan ◽  
R. Karthikeyan ◽  
S. Prashanth ◽  
B. Rohith Reddy

The Aluminum Metal Matrix Composites (AMMCs) have been becoming suitable materials for many devices in the application of various fields like heavy equipment’s industry, automobile, aeronautics and etc. because of its excellent physical and structural characteristics. The research on AMMC dealt the effect of reinforcement such as fly-ash, SiC, Al2O3, Graphite, B4C, Cubic Boron Nitride (CBN) on aluminium in different percentages. Every reinforcement has its own characteristics that enhance the base aluminium characteristics when added. By adding these types of reinforcement to metal base led to enhance the properties like wear resistance, stiffness, creep, tensile strength, fatigue, toughness, thermal conductivity, hardness in comparison with traditional approach on materials engineering. This review paper was aimed to give the detailed information about the impact of various reinforcements incorporated in matrix by illustrating its benefits and drawbacks. This extensive survey on AMMC could be useful to develop farther.


2012 ◽  
Vol 424-425 ◽  
pp. 848-851 ◽  
Author(s):  
Qing Hua Zou

The experiment on adding rare earth elements doped in diamond matrix composites is made. Based on the doping of rare earth in metal powders including tungsten carbide, iron and nickel, Co is entirely replaced by Fe with rare earth in diamond matrix composites, and the process route of rare earth doping is indicated. The related performance of is measured, and the results obtained show that the bending strength, the hardness and the impact ductility of Fe matrix composites with rare earth are improved. The practical service performance of Fe matrix composites with rare earth has reached up to the practical service performance of Co matrix, and bearing good practical service performance, low price, have made corresponding diamond tools.


2004 ◽  
Vol 16 (05) ◽  
pp. 244-250 ◽  
Author(s):  
LI-TUNG CHANG ◽  
KUEN-HORNG TSAI ◽  
JIN-SHAN SHIAU

Rubber tiles are popular in playgrounds as protective surfacing to reduce the incidence of head injuries caused by children falling from equipment. However, Taiwan has not yet established a test code for assessment of the shock-absorption properties of such surfacing. For this study, an experimental model was established to evaluate the behavior of various rubber tiles. A hemispherical headform was dropped from a set height to strike the center of the specimen tile. The peak acceleration and Head Injury Criterion (HIC) were measured to assess the impact absorption of and critical height for a given rubber tile. The results show that utilization of the HIC index provides a more conservative assessment of the shock absorption and, ultimately, protection from head injuries than peak acceleration. The maximum critical heights of the rubber tiles used in this study for tile thicknesses of 45, 60 and 80 mm were 1.6, 2.0 and 2.2 m, respectively. Two-part rubber tiles with a base structure consisting of a box-like core offer superior protection from head injuries relative to analogous cylindrical, square pillar and solid structures. The maximum differences in peakacceleration and HIC values comparing the box-like core and solid structures at a thickness of 45 mm were 21% and 44%, respectively. The results of this study suggest a minimum of rubber thickness of 60 mm, based on probable maximum fall heights of more than 1.6 m. Moreover, incorporation of an appropriate cushioning structure in the base of the rubber tile could further improve protection.


Author(s):  
Julieta Kaleicheva ◽  
Krasimir Kirov ◽  
Valentin Plamenov Mishev ◽  
Zdravka Karaguiozova

The microstructure and mechanical properties of high chromium white cast iron with composition: 2,6÷3,4% C; 0,9÷1,1% Si; 0,8÷1,1% Mn; 1,0÷1,3% Mo; 12,3÷13,4% Cr, additionally doped with boron in an amount of 0,18% to 1,25% is investigated. The microstructure of six compositions of white cast irons is studied by means of an optical metallographic analysis - one without boron, and the others contain 0,18%; 0,23%; 0,59%; 0,96% and 1,25% boron. A test is performed to determine: hardness by the Rockwell method; microhardness; bending strength and impact toughness. It was found that at a boron content of 0,18%; 0,23% and 0,59%, the structure of white cast irons is subeutectic, with impact toughness in the range of 1,80÷1,52 J/cm2; with a boron content of 0,96%, the structure of white cast iron is close to the eutectic, with impact toughness 0,98 J/cm2 ; at a boron content of 1,25% the structure of white cast iron is supereutectic and the impact toughness decreases to 0,68 J/cm2. With a change in the boron content from 0,8% to 1,25%, the amount of carbide phase in the structure of white cast iron increases, which leads to an increase in hardness from 53 to 59 HRC. The highest bending strength (Rmi=660,85 MPa) was obtained in white cast irons with a boron content of 0,23%. 


Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Agnieszka Nowak-Brzezińska

Decision support systems founded on rule-based knowledge representation should be equipped with rule management mechanisms. Effective exploration of new knowledge in every domain of human life requires new algorithms of knowledge organization and a thorough search of the created data structures. In this work, the author introduces an optimization of both the knowledge base structure and the inference algorithm. Hence, a new, hierarchically organized knowledge base structure is proposed as it draws on the cluster analysis method and a new forward-chaining inference algorithm which searches only the so-called representatives of rule clusters. Making use of the similarity approach, the algorithm tries to discover new facts (new knowledge) from rules and facts already known. The author defines and analyses four various representative generation methods for rule clusters. Experimental results contain the analysis of the impact of the proposed methods on the efficiency of a decision support system with such knowledge representation. In order to do this, four representative generation methods and various types of clustering parameters (similarity measure, clustering methods, etc.) were examined. As can be seen, the proposed modification of both the structure of knowledge base and the inference algorithm has yielded satisfactory results.


2016 ◽  
Vol 61 (4) ◽  
pp. 1985-1990
Author(s):  
A. N. Wieczorek

Abstract The paper presents results of the wear tests of chain wheels made of austempered ductile iron with various content of residual austenite. The aim of this study was to demonstrate the impact of the dynamic surface treatment (shot peening) on wear properties of surface layers of the chain wheels tested that were subjected to the action of quartz abrasive. Apart from determining the value of the abrasive wear, examinations of the magnetic phase content in the microstructure were carried out and plots of hardness of the surface layer as a function of the distance from the surface and microstructure of the materials were prepared. Based on the results, the following was found: an increase in the abrasive wear and a reduction in the hardness of the surface layer of chain wheels subjected to shot peening, as well as reduction of susceptibility to negative action of the shot for cast irons with the structure of upper ausferrite.


2013 ◽  
Vol 58 (3) ◽  
pp. 895-897 ◽  
Author(s):  
S. Byelikov ◽  
I. Volchok ◽  
V. Netrebko

Abstract It is shown that chromium distribution in the metal base of high-chromium cast irons depends on manganese content. According to the X-ray micro-spectral analysis data with the increase of manganese content from 0.72 to 6.49% chromium content decreased in the near-carbide zones. At the same time chromium content in carbides increased. This process obtained particularly strong development inside eutectic colonies of carbides. As a result of it, when total chromium content in the alloy has been 23%, its concentration in the local zones was 12,3%, thus the necessary level of corrosion resistance has not been provided. The minimal chromium content has to amount 23.2%, at 6.49% Mn and 2.2...2.5% C in order to provide corrosion resistance of high-chromium cast irons


2012 ◽  
Vol 430-432 ◽  
pp. 281-284 ◽  
Author(s):  
Yun Bo Lei ◽  
Xue Juan Cao

The curing rate of epoxy/Versamid 125 (V125) by heating curing, room-temperature curing and microwave curing was compared. It is founded that applying microwave technology could effectively improve the curing rate and the curing time is only 3-4minutes. 140W microwave could cure the epoxy system in good condition, but 280W and 420W were easy to make the materials coking. The impact of diluent on mechnical properties of curing product were studied and it is showed that the impact strength increases and the impact ductility will be improved with the content of diluent increases, while the compressing strength, bending strength and tensile strength decrease.


2013 ◽  
Vol 380-384 ◽  
pp. 3082-3085 ◽  
Author(s):  
Jian Zhuang ◽  
Wei Hu ◽  
Da Ming Wu ◽  
Ya Jun Zhang ◽  
Zhong Li Zhao ◽  
...  

With successful development of LED lamps, the dissipation of LED lamps has become the core problem. If the heat produced during the work cant be loss in time, the high temperature of the lamps will affect their service lives or even damage the LED permanently. In this paper, based on the principle of finite element method, using thermal simulation software, the effect of the geometric characteristics micro-structure of the heat exchanger combining polymer micro-scale fins and metal base on the heat transfer characteristics was simulated. The impact of the fin width, wing fin pitch, fin height and thickness of the substrate on the tablet microstructure heat transfer characteristics was analyzed. The results provide some technical reference for the design and application of the micro heat exchanger.


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