• 제목/요약/키워드: die pressing

검색결과 117건 처리시간 0.024초

금형압축 하에서 공구강 분말의 1단계 압축거동 (Stage 1 compaction behavior of tool steel under die pressing)

  • 김기태;김종성
    • 대한기계학회논문집A
    • /
    • 제21권7호
    • /
    • pp.1073-1080
    • /
    • 1997
  • The stage 1 compaction behavior of tool steel powder under die pressing was studied. The friction effects between the powder and the die wall under different die pressing modes were also investigated. The elastoplastic constitutive equations based on the yield functions by Fleck et al. and by Shima and Oyane were implemented into a finite element program to simulate die compaction processes. Finite element calculations were compared with experimental data for densification and density distribution of tool steel powder under single and double action die pressing. Finite element calculations using the yield function by Fleck et al. agreed better with experimental data than by Shima and Oyane.

금속분말의 냉간금형 압축 해석 (Analysis for Cold Die Compaction of Meteal Powder)

  • 권영삼;이희태;김기태
    • 대한기계학회논문집A
    • /
    • 제20권6호
    • /
    • pp.1893-1902
    • /
    • 1996
  • Densification behavior of 316L stainless steel power under die pressing was studied. The efects of friction between the powder and die wall under different die pressing modes were also investigated. The elastoplastic constitutive equations based on the yield functions of Fleck-Gurson and of Shima and Oyane were implemented into finite element program(ABAQUS) to simulate die compaction processes. The finite element results were compared with experimental data for 316L stainless steel powder under die pressing.

금속 몰드를 이용한 금속 분말의 온간 등가압 성형 (Densification Behavior of Metal Powder Under Warm Isostatic Pressing with a Metal Mold)

  • 박중구;김기태
    • 대한기계학회논문집A
    • /
    • 제28권6호
    • /
    • pp.838-847
    • /
    • 2004
  • The effect of a metal mold on densification behavior of stainless steel 316L powder was investigated under warm isostatic pressing with a metal mold. We use lead as a metal mold and obtain experimental data of metal mold properties. To simulate densification behavior of metal powder, elastoplastic constitutive equation proposed by Shima and Oyane was implemented into a finite element program (ABAQUS) under warm die pressing and warm isostatic pressing with a metal mold. Finite element results were compared with experimental data for densification and deformation of metal powder under warm isostatic pressing and warm die pressing.

금속 몰드를 이용한 금속 분말의 온간 등가압 성형 (Densification behavior of metal powder under warm isostaic pessing with metal mold)

  • 박중구;김기태
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2003년도 추계학술대회
    • /
    • pp.1352-1357
    • /
    • 2003
  • The effect of the metal mold on densification behavior of stainless steel 316L powder was investigated under warm isostatic pressing with metal mold. We use lead as metal mold and obtain experimental data of metal mold property. To simulate densification of metal powder, the elastoplastic constitutive equation proposed by Shima and Oyane was implemented into a finite element program (ABAQUS) under warm die pressing and warm isostatic pressing with metal mold. Finite element results were compared with experimental data for densification and deformation of metal powder under warm isostatic pressing and warm die pressing.

  • PDF

냉간 인서트 금형용 Mo, V 무첨가 저합금 주강의 주요 성질에 미치는 Si함량의 영향 (The Effect of Si Content on Important Properties of A Mo and V Free Low Alloy Cast Steel for The Insert of Cold Pressing Die)

  • 신제식;김봉환;문병문
    • 한국주조공학회지
    • /
    • 제29권2호
    • /
    • pp.70-77
    • /
    • 2009
  • The aim of this study was to develop a Mo and V free low alloy cast steel materials, enabling the significant cost- and time-savings in manufacturing and maintaining the insert of cold pressing die without impairment of the important properties. For this purpose, the effects of Si content on combinations of important properties such as hardness, hardenability, and weldability, and strength were systematically investigated. In order to evaluate the applicability as the insert of cold pressing die, the mechanical properties were measured after spheroidization annealing, quenching and tempering, and flame hardening heat treatments, respectively. After the Q/T and F.H. treatments, the developed 0.8${\sim}$1.6%Si containing Mo and V free low alloy cast steels showed excellent matrix strengthening effect, hardenability, and weldability, fulfilling the industrial criterion of the mechanical properties for automobile cold pressing die insert.

Coercivity of Hot-pressed Compacts of Nd-Fe-B-type HDDR-treated Powder

  • Abdul Matin, Md.;Kwon, Hae-Woong;Lee, Jung-Goo;Yu, Ji-Hun
    • Journal of Magnetics
    • /
    • 제19권2호
    • /
    • pp.106-110
    • /
    • 2014
  • $Nd_{12.5}Fe_{80.6}B_{6.4}Ga_{0.3}Nb_{0.2}$ HDDR-treated powder was compacted by hot-pressing using different configurations of dies and heating rates. The die configurations were especially different in terms of the evacuation system that was used in heating for hot-pressing. The coercivity in the compacts was influenced by the evacuation system of the die and heating rate. In spite of the identical hot-pressing temperature and heating rate, coercivity was radically reduced above $600^{\circ}C$ in the compacts prepared in the closed-type die compared to that in the compacts prepared in the open-type die. The coercivity in the compacts prepared in the closed-type die decreased with increasing heating rate and the value further increased when extreme high heating rate was employed. $Nd_{12.5}Fe_{80.6}B_{6.4}Ga_{0.3}Nb_{0.2}$ HDDR-treated powder contained a significant amount of residual hydrogen (approx. 1500 ppm) in the form of $Nd_2Fe_{14}BH_x$ hydride. The dramatic coercivity decrease in the compact prepared in the closed die is attributed to the disproportionation of $Nd_2Fe_{14}BH_x$ hydride. High coercivity is mainly due to the effective desorption of hydrogen or the suppression of hydrogen-related disproportionation upon hot-pressing.

온간 성형 하에서 A1 합금 분말의 정밀정형에 대한 유한요소해석 (A Finite Element Analysis for Near-net-shape Forming of A16061 Powder under Warm Pressing)

  • 김종광;양훈철;김기태
    • 대한기계학회논문집A
    • /
    • 제27권11호
    • /
    • pp.1897-1906
    • /
    • 2003
  • A finite element analysis for near-net-shape forming of A16061 powder was performed under warm rubber isostatic pressing and warm die pressing. The advantages of warm compaction by rubber isostatic pressing were discussed to obtain a part with better density distributions. The shape of rubber mold was designed by determining a cavity shape that provides a desired shape of the final powder compact. To simulate densification and deformed shape of a powder compact during pressing, the elastoplastic constitutive equation based on yield function of Shima-Oyane was implemented into a finite element program(ABAQUS). The hyperelastic constitutive equation based on the Ogden strain energy Potential was employed to analyze nonlinear elastic response of rubber. Finite element results were compared with experimental data for Al6061 powder compacts under warm die pressing and warm isostatic pressing.

Deep Drawing With Internal Air-Pressing to Increase The Limit Drawing Ratio of Aluminum Sheet

  • Moon, Young-Hoon;Kang, Yong-Kee;Park, Jin-Wook;Gong, Sung-Rak
    • Journal of Mechanical Science and Technology
    • /
    • 제15권4호
    • /
    • pp.459-464
    • /
    • 2001
  • The effects of internal air-pressing on deep drawability are investigated in this study to increase the deep drawability of aluminum sheet. The conventional deep drawing process is limited to a certain limit drawing ratio(LDR) beyond which failure will occur. The intention of this work is to examine the possibilities of relaxing the above limitation through the deep drawing with internal air-pressing, aiming towards a process with an increased drawing ratio. The idea which may lead to this goal is the use of special punch that can exert high pressure on the internal surface of deforming sheet during the deep drawing process. Over the ranges of conditions investigated for Al-1050, the local strain concentration at punch nose radius area was decreased by internal air-pressing of punch, and the deep drawing with internal air-pressing was proved to be very effective process for obtaining higher LDR.

  • PDF

등통로각압축 (ECAP) 공정에서 다이 마찰 효과에 대한 수치적 연구 (A Numerical Investigateion of the Effect of Die Friction in ECAP (Equal Channel Angular Pressing))

  • 서민홍;김형섭
    • 소성∙가공
    • /
    • 제9권3호
    • /
    • pp.219-225
    • /
    • 2000
  • Equal channel angular pressing (ECAP) is a convenient forming process to extrude material without substantial changes in the sample geometry and this deformation process gives rise to produce ultrafine grained materials. The properties of the materials are strongly dependent on the plastic deformation behaviour during ECAP. The major process variables during ECAP are 1) die geometries, such as a channel angle and coner angles, and 2) the processes variables, such as lubrication and deformation speed. In this study, the plastic deformation behaviour of materials during the ECAP has been theoretically analysed by the finite element method (FEM). The effect of the die friction on the plastic deformation behaviour during the pressing is discussed by means of FEM calculations.

  • PDF

Pure-Zr의 ECAP 공정에서 마찰에 따른 금형의 소성 변형 (Plastic Deformation of Die due to Friction during Equal Channel Angular Pressing)

  • 배강호;권기환;채수원;권숙인;김명호;황성근
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 추계학술대회 논문집
    • /
    • pp.804-807
    • /
    • 1997
  • Recently equal-channel angular pressing (ECAP) has been employed to produce ultra-fine grain size materials. In this paper pure-Zirconium is considered due to its applicability to nuclear reactors. Among many process parameters of ECAP frictional effect on the plastic deformation of die has been investigated. The back pressure effect due to friction increases the stress level of die especially at the crossing area of channels, which may result in plastic deformation of die. The finite element method has been employed to investigate this issue.

  • PDF