• 제목/요약/키워드: Die-casting Parts

검색결과 76건 처리시간 0.024초

Numerical and Experimental Study of Semi-solid A356 Aluminum Alloy in Rheo-Forging process

  • 김현호;강충길
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2009년도 추계학술대회 논문집
    • /
    • pp.371-374
    • /
    • 2009
  • 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.

  • PDF

Thixoforging Process에 의하여 제조한 금속복합재료 실린더라이너 부품의 기계적 특성 평가 (Mechanical Characteristics Evaluation of Metal Matrix Composites Cylinder Linear Fabricated by Thixoforging Process)

  • 허재찬;이승후;강충길
    • 한국정밀공학회지
    • /
    • 제20권2호
    • /
    • pp.58-65
    • /
    • 2003
  • The conventional forming process such as squeeze casting or die casting for fabricating metal matrix composites products have a disadvantage such as non homogenous distribution of reinforcement, weak bonding between matrix and reinforcement and cost increase in parts fabrication. Thixoforming process has been accepted as a new method for fabricating the net shaped metal matrix composites with lightweight and wear resistance. In this paper, the effect of volume fraction and reinforcement sizes on mechanical properties in cylinder liner part of metal matrix composites has been investigated with processes parameters such as pressure and velocity. Moreover, the methods to obtain the thixoforged composites cylinder liner with high quality has been proposed. To evaluate the composites cylinder linear fabricated at the conditions proposed in this study, mechanical properties of fabricated composites cylinder linear were compared with those of commercial composites cylinder linear.

알루미늄 소재의 레오로지 직접단조공정에서 가압력이 액상 편석에 미치는 영향 (The Effect of Pressure on Liquid Segregation in Direct Rheo-Forging Process of Aluminum Alloys)

  • 오세웅;배정운;강충길
    • 소성∙가공
    • /
    • 제16권3호
    • /
    • pp.178-186
    • /
    • 2007
  • Rheo-forging process of aluminum alloy is suitable for large parts of net shape without defects and excellent mechanical properties in comparison with conventional die casting and forging process. To control the microstructure of the product with high mechanical properties in rheo-forming, solid fraction is required to prevent porosity and liquid segregation. Therefore, in rheo-forging process, die shape, pressure type and solid fraction are very important parameters. The defects such as porosity, liquid segregation and unfitting phenomena occur during rheo-forging process. To prevent these defects, mechanical properties and microstructure analysis of samples versus the change of pressure are carried out and the problem and its solutions are proposed. Also, the mechanical properties versus various pressures were compared with and without heat treatment. The alloys used for rheo-forming are A356 and 2024 aluminum alloy. The rheology material is fabricated by electromagnetic process with controlling current and stirring time.

광조형물의 표면 조도 향상에 관한 연구 -파라핀 코팅과 연삭 후처리 공정 이용- (A Study on Improving the Surface Roughness of Stereolithography Parts -Using Paraffin Coating and Grinding Postprocess-)

  • 안대건;김호찬;이석희
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2001년도 춘계학술대회 논문집
    • /
    • pp.45-48
    • /
    • 2001
  • SL(Stereolithogrphy) part is made by piling up thin layers which causes the stair stepping effect at the surface of SL parts. This effect causes excessive surface roughness and requires additional postprocess finishing such as abrasive basting which is detrimental to part geometry and time consuming. Hence paraffin coating and grinding postprocess is proposed to raise the surface quality of SL part. The paraffin which has suitable properties for the proposed postprocess is coated all over the part surface. By grinding the thin layer of coated on the SL part only, the surface roughness can be improved without any damage on the part. From the experimental result, It is verified as very practical for die casting with silicon rubber mold.

  • PDF

다이캐스팅 보의 등가 기공결함을 고려한 강도평가 (Strength Estimation of Die Cast Beams Considering Equivalent Porous Defects)

  • 박문식
    • 대한기계학회논문집A
    • /
    • 제41권5호
    • /
    • pp.337-343
    • /
    • 2017
  • 각종 기공과 같은 결함을 허용하는 다이캐스팅 부품의 강도를 현장 수준에서 평가할 수 있는 이론적 방법을 제안한다. 결함을 갖는 부재의 탄성시험을 통해 강성도를 구하고 이를 결함이 없는 이론적 강성도와 비교함으로써 등가 기공률을 산출한다. 등가 기공률 식은 Eshelby의 함유이론으로부터 유도하였다. 산출된 등가 기공률은 Mori-Tanaka 법을 이용하여 기공결함을 포함하는 재료의 응력-변형률 선도를 그리기 위하여 사용된다. 본 연구에서는 Hollomon 변형경화 모델을 사용하였다. 이 응력-변형률 선도를 이용하면 균일분포의 기공결함을 갖는 다이캐스팅 부재의 강도를 평가할 수 있게 된다. 등가 기공률을 고려한 하나의 이론해로서 직사각형 단면의 다이캐스팅 보에 대한 삼점 굽힘의 탄소성 강도를 소성힌지의 방법으로 유도하였다.

가압함침법에 의한 $Al_2O_3/Al$ 복합재료의 기공 및 편석의 발생에 대한 분석연구 (Analysis of the Formation of Porosity and Segregation in $Al_2O_3/Al$ Composites by Squeeze Infiltration Method)

  • 서영호;이형국
    • 한국주조공학회지
    • /
    • 제21권3호
    • /
    • pp.163-178
    • /
    • 2001
  • The squeeze infiltration process is potentially of considerable industrial importance. The performance enhancements resulting from incorporation of short alumina fiber into aluminum are well documented. These are particularly significant for certain automobile components. Aluminum matrix composite automotive parts, such as diesel engine pistons or engine blocks are produced using squeeze casting apparatus or pressure die-casting apparatus. But the solidification process gets complicated with manufacturing parameters and the factors for porosity formation have not fully understood yet. In this study the formation of porosity during squeeze infiltration has been studied experimentally to achieve an improved understanding of the squeeze infiltration process for manufacture of short-fiber-reinforced components, particularly the mechanism of porosity formation. Al-based MMCs produced under a range of conditions were examined metallographically and the porosity characterised;a kind of matrix, an initial temperature of melt, and a volume fraction of reinforcement. The densimetry and the microscopic image analysis were done to measure the amount of porosity. A correlation between manufacturing parameters and defects was investigated through these.

  • PDF

Mg-Al 합금의 크리프 거동에 미치는 합금원소의 영향 (Effect of Alloying Elements on Creep Behavior of Mg-Al Alloys)

  • 임현규;김세광;김도향
    • 한국주조공학회지
    • /
    • 제32권1호
    • /
    • pp.44-49
    • /
    • 2012
  • In this study, three magnesium alloys were investigated; those are 1.5wt.% CaO added AM80, 1.0wt.% CaO added AM60, and conventional MRI153 alloys. Test specimens of three alloys were prepared by re-melting and casting into steel mold with ingots and machining. The mechanical properties and the creep behavior at 150 degrees Celsius of these specimens were determined and their microstructures were characterized using OM and SEM. For the application to die-casting, fluidity test were carried out with spiral mold. Compared with 1.0wt.% CaO added AM60 alloy, 1.5wt.% CaO added AM80 alloy exhibited good creep properties in all test conditions. Moreover, CaO added alloys showed better creep properties than MRI153 alloy at lower load condition. It is proposed that 1.5wt.% CaO added AM80 alloy is useful to apply to power-train parts such as transmission case in vehicles.

자동차 허브의 내경 및 평행도 자동검사 시스템에 대한 연구 (A study on the automatic inspection system for inner diameter and parallelism of automobile hubs)

  • 강병수;유형민
    • Design & Manufacturing
    • /
    • 제16권3호
    • /
    • pp.16-21
    • /
    • 2022
  • In order to reduce the weight of parts and materials for the development of high-efficiency engines in accordance with the strengthening of automobile fuel efficiency regulations, the existing casting material is changed to a iron plate material, and plastic processing and turning operations are performed to lighten the weight and reduce the manufacturing cost. Among the pulley components applied to the damper pulley, the HUB product was manufactured by plastic machining instead of the existing casting process, and the inspection standardized for automating the inner diameter and parallelism measurement of the turning result of the new hub part with improved quality, and the inspection system for this Development of design and operation software to automate the inspection of the inner diameter and parallelism of the hub was described. The representative specifications of the development equipment are a hub inner diameter 22mm inspection system, a three-point inspection system with a parallelism of 0.15mm on the top.

마그네슘 사출성형 공정에 관한 연구 (Research for Magnesium Injection Molding Process)

  • 강태호;김인관;김영수
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2002년도 춘계학술대회 논문집
    • /
    • pp.882-885
    • /
    • 2002
  • Magnesium alloys are very attractive materials for appling to the development of autemobile parts or electric goods where light weight and higher stiffness. Due to higher ratio of strength vs. weight and stillness vs. weight, various magnesium alloys are well applied in much weight saving design applications though extrusion or die-casting process. However for the requisites of higher strength and weight savings, some new fabrication processes has been and it can be realized though the aid of injection modeling technology. To obtain the parametric data base for the injection molding process, various experiments were executed for AZ91D magnesium alloy. This paper propose the optimum condition of injection temperature, first and second pressure. the process was lined-up successfully often changing the injection unit. fluid pressure system from the conventional plastic injection molding process.

  • PDF

경량 밸브 제조용 마그네슘 합금의 고온 성형 특성 (Characteristics of Hot Forming of Magnesium Alloys for Light-weight Valves)

  • 박준홍;이준호
    • 한국기계가공학회지
    • /
    • 제11권4호
    • /
    • pp.173-179
    • /
    • 2012
  • In recent years, Magnesium(Mg) and its alloys have become a center of special interest in the automotive industry. Due to their high specific mechanical properties, they offer a significant weight saving potential in modern vehicle constructions. Most Mg alloys show very good machinability and processability, and even the most complicated die casting parts can be easily produced. In this study, Microstructure, Vickers hardness and tensile tests were examined and performed for each specimen to verify effects of forming conditions. Also to verify upsettability and forming limit of the specimen at room temperature and elevated temperature, upsetting experiments were performed. For comparison, experiments at elevated temperature were performed for various Mg alloy, such as AZ31, AZ91, and AM50. The experimental results were compared with those of CAE analysis to propose forming limit of Magnesium alloys.