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Optimal Reheating Condition of Semi-solid Material in Semi-solid Forging by Neural Network
Park, Jae-Chan,Kim, Young-Ho,Park, Joon-Hong Korean Society for Precision Engineering 2003 International Journal of the Korean Society of Pre Vol.4 No.2
As semi-solid forging (SSF) is compared with conventional casting such as gravity die-casting and squeeze casting, the product without inner defects can be obtained from semi-solid forming and globular microstructure as well. Generally, SSF consists of reheating, forging, and ejecting processes. In the reheating process, the materials are heated up to the temperature between the solidus and liquidus line at which the materials exists in the form of liquid-solid mixture. The process variables such as reheating time, reheating temperature, reheating holding time, and induction heating power has large effect on the quality of the reheated billets. It is difficult to consider all the variables at the same time for predicting the quality. In this paper, Taguchi method, regression analysis and neural network were applied to analyze the relationship between processing conditions and solid fraction. A356 alloy was used for the present study, and the learning data were extracted from the reheating experiments. Results by neural network were in good agreement with those by experiment. Polynominal regression analysis was formulated using the test data from neural network. Optimum processing condition was calculated to minimize the grain size and solid fraction standard deviation or to maximize the specimen temperature average. Discussion is given about reheating process of row material and results are presented with regard to accurate process variables fur proper solid fraction, specimen temperature and grain size.
가압단조 방법에 의한 알루미늄 반응고 성형해석에 관한 연구
김미애(Mi-Ae Kim),차용훈(Young-Hun Cha),성백섭(Back-Sub Sung),김정대(Jung-Dae Kim),장훈(Hoon Jang),홍지민(Ji-Min Hong) 한국생산제조학회 2006 한국생산제조시스템학회 학술발표대회 논문집 Vol.2006 No.5
In a recent trend where an industry is highly advanced and an environment preservation is emphasized, They also perform various researches on improving production process and developing new systems. In the pressing forging process among the semi-solid casting process, heated aluminum alloy turns into a semisolid state mixed with solid and fluid around at the fusion point. The solid is achieve in dendrite which remains in a fine solid state of globular shape stuck together. If it is placed in the mold, it maintains its shape independently like the solid. If it is pressed, it comes to have the state similar to the fluid and consequently is easily cast in the metal mold. It also aims to estimate the exact casting state of product through Super forge 2005, a program to interpret finite factors in order to perform forge die casting of plate in the middle of valve body in the car automatic transmission. Furthermore, it assesses the change of the distribution and transformation ratio.
김미애(M.A. Kim),장훈(H. Jang),장경천(K.C. Jang),이동길(D.K. Lee),차용훈(H..Y. Cha) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
In a recent trend where an industry is highly advanced and an environment preservation is emphasized, They also perform various researches on improving production process and developing new systems. In the pressing forging process among the semi-solid casting process, heated aluminum alloy turns into a semisolid state mixed with solid and fluid around at the fusion point. The solid is achieved in dendrite which remains in a fine solid state of globular shape stuck together. If it is placed in the mold, it maintains its shape independently like the solid. If it is pressed, it comes to have the state similar to the fluid and consequently is easily cast in the metal mold. It also aims to estimate the exact casting state of product through Super forge 2005, a program to interpret finite factors in order to perform forge die casting of plate in the middle of valve body in the car automatic transmission. Furthermore, it assesses the change of the distribution and transformation ratio.
강대진(Dae-Jin Kang) 산업기술교육훈련학회 2007 산업기술연구논문지 (JITR) Vol.12 No.2
The casting defects that are caused by molten metal were cold shut formation, entrapment of air, gas, and inclusion. But the control of casting defects has been based on the experience of the foundry engineers.In this thesis, the computer simulation analyzed the flow of molten metal. The quantitative analyses which proposed the effective mold design was executed Flow patterns of 0.15-0.16m/s molten metal in 15mm thin plate casting were investigated in order to optimize die-casting process. As increasing ingate velocity in thin plate casting, cold shot was decreased. The parameters of runner shape that affected on the optimized conditions that was calculated with simple equation were investigated. These die casting process control techniques of automobile valve body mid-plate have achieved good agreement with the experimental data of tensile strength, hardness test, and material structure photographies satisfactory results.
Numerical and Experimental Study of Semi-solid A356 Aluminum Alloy in Rheo-Forging process
H. H. Kim,C. G. Kang 한국소성가공학회 2009 한국소성가공학회 학술대회 논문집 Vol.2009 No.10
Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D. Samples of metal parts were subsequently fabricated by using hydraulic press machinery.
Computer-assisted Rheo-forging Processing of A356 Aluminum Alloys
H.H. Kim,C.G. Kang 한국소성가공학회 2010 기타자료 Vol.2010 No.6
Die casting process has been used widely for complex automotive products such as the knuckle, arm and etc. Generally, a part fabricated by casting has limited strength due to manufacturing defects by origin such as the dendrite structure and segregation. As an attempt to offer a solution to these problems, forging has been used as an alternative process. However, the forging process provides limited formability for complex shape products. Rheo-forging of metal offers not only superior mechanical strength but also requires significantly lower machine loads than solid forming processes. In order to produce semi-solid materials of the desired microstructure, a stirring process is applied during solidification of A356 aluminum molten state. This paper presents the results of an A356 aluminum alloy sample, which were obtained by experiment and by simulation using DEFORM 3D V6.1. Samples of metal parts were subsequently fabricated by using hydraulic press machinery. In order to compare the influence of loading method, two types of samples were fabricated: (1) samples fabricated under direct loading die sets (2) those fabricated under indirect loading die sets. The formability and defects, which were predicted by FEM simulation, were similar to those of samples used in practice.
가압단조 방법에 의한 알루미늄 반응고 성형해석에 관한 연구
김미애(Mi-Ae Kim),차용훈(Young-Hun Cha),성백섭(Back-Sub Sung),김정대(Jung-Dae Kim),장훈(Hoon Jang),홍지민(Ji-Min Hong) 한국생산제조학회 2006 한국공작기계학회 춘계학술대회논문집 Vol.2006 No.-
In a recent trend where an industry is highly advanced and an environment preservation is emphasized, They also perform various researches on improving production process and developing new systems. In the pressing forging process among the semi-solid casting process, heated aluminum alloy turns into a semisolid state mixed with solid and fluid around at the fusion point. The solid is achieve in dendrite which remains in a fine solid state of globular shape stuck together. If it is placed in the mold, it maintains its shape independently like the solid. If it is pressed, it comes to have the state similar to the fluid and consequently is easily cast in the metal mold. It also aims to estimate the exact casting state of product through Super forge 2005, a program to interpret finite factors in order to perform forge die casting of plate in the middle of valve body in the car automatic transmission. Furthermore, it assesses the change of the distribution and transformation ratio.
진철규(C. K. Jin),장창현(C. H. Jang),정민근(M. K. Jung),강충길(C. G. Kang) 한국소성가공학회 2014 한국소성가공학회 학술대회 논문집 Vol.2014 No.10
Thin metallic plate with micro-pattern can be applied to useful products such as electrical and automobile parts, bipolar plates in fuel cells, and plate heat exchangers, etc. There are several processes to manufacture thin metallic plate such as stamping, rubber forming, vacuum die-casting, and semi-solid forming. This paper introduces forming processes for bipolar plate in fuel cells. In stamping and rubber forming, aluminum, stainless steel, and titanium could be used for bipolar plate. In vacuum die casting and semi-solid forming, only aluminum could be used but very precise and soundness bipolar plate was manufactured.