Semisolid metal processing

Fan, Z.

doi:10.1179/095066001225001076

Cited by 822 publications

(437 citation statements)

References 93 publications

Supporting

Mentioning

399

Contrasting

Unclassified

Order By: Relevance

“…반응고 주조 공정은 복잡하고 정밀성을 요구하는 제품을 제작 하는데 유리하며, 특히 Mg 합금의 반응고 주조공정은 Mg 합 금의 전자파 차폐, 비강도 우수성, 고댐핑 특성 때문에 IT제품 을 비롯하여 자동차, 항공기, 선박 등 산업 전반에 걸쳐 차세대 응용 분야로 각광 받고 있다 (1~4) . 틱소몰딩 공정은 다이캐스팅 공법에서의 액상주조와는 달리 액상과 고상이 혼재하는 슬러시(slurry) 형태로 사출이 이루어 지기 때문에 미세조직의 배열이 우수하고, 기공과 변형의 발생 이 적어 강도가 우수하며, 미세성형이 가능하다 (5,6) . 또한, 다이 캐스팅이 705℃ 이상에서 이루어지는데 비하여 틱소몰딩 공정 은 560~610℃에서 반응고 주조의 형태로 성형이 이루어지기 때문에 다이캐스팅에 비하여 미세조직이 균일하고, 금형의 수 명도 우수하다 (5~6) .…”

Section: 서 론unclassified

Improvement in Mechanical Properties of AZ91D Mg-Alloy through Thixomolding Process

Shin¹,

Chung

2012

Journal of manufacturing engineering & technology

View full text Add to dashboard Cite

Thixomolding of Mg-alloy is a semi-solid injection molding process utilizing thixotropic phenomenon. Using this process, higher strength, thinner wall section and tighter tolerance without porosity are obtained. It has been applied for production of near-net-shape magnesium component. To design optimal thixomolding process of Mg-alloy part, molding conditions such as slurry temperature, mold temperature and injection time should be determined properly. Selection of these parameters has been dependent upon engineers' experience and intuitiveness. In this paper, to improve mechanical properties of the thixomolded product, optimal selection of process variables such as injection velocity, barrel temperature and die temperature in the process has been studied through microstructural analysis and Taguchi method. Performance of the process is verified through experiments.

show abstract

Section: 서 론unclassified

Improvement in Mechanical Properties of AZ91D Mg-Alloy through Thixomolding Process

Shin¹,

Chung

2012

Journal of manufacturing engineering & technology

View full text Add to dashboard Cite

show abstract

“…From the microstructure-mechanical property relationship in SSF sample, Fan proposed that the SSF microstructure was similar to that of a metal toughened ceramic matrix composite [7]. In fact, as the constituents of SSF microstructure are all metals, it is more similar to a metal matrix composite.…”

Section: Introductionmentioning

confidence: 95%

Effects of Mg and RE additions on the semi-solid microstructure of a zinc alloy ZA27

Chen

Yuan

Sun

et al. 2003

Science and Technology of Advanced Materials

View full text Add to dashboard Cite

The effects of 2 mass% Mg and 0.8 mass% RE additions on the microstructural evolution of a Zr modified zinc alloy ZA27 during isothermal holding at semi-solid temperature of 460 8C have been studied by optical microscope and scanning electron microscope. Results show that these two elements all decrease the coarsening rate of solid primary particles, and improve the uniformity of particle size. The addition of Mg greatly decreases the solid fraction, and then increases the distance between particles. However, the element of RE mainly concentrates at the liquid regions between particles, and hinders both the atom diffusion and the welding of contact particles. In addition, the behaviors of particle coarsening of these two alloys, together with that of the Zr modified ZA27 alloy without the other elements, obey the LSW law after the three semi-solid systems reach at their solid-liquid equilibrium states. The additions of these two elements have no visible effect on the shape factor of particles. q

show abstract

“…Ultrasonic processing of liquid metals is one of the routes for obtaining spheroidal microstructure. [27] The aim in this study is to thixoform ultrasonically processed MMNCs and to test the mechanical properties. The major challenges are ensuring that the nanoparticles are wetted and dispersed reasonably evenly.…”

Section: Metal Matrix Nanocomposites (Mmncs)mentioning

confidence: 99%

“…Thixoforming, which involves reheating a solid slug to the semi-solid state and forming it with a liquid fraction between 30 and 50 pct, offers improved mechanical properties over conventional casting, because the semisolid metal flow is laminar rather than turbulent, hence reducing porosity. Also, thixoforming allows components to be produced with more complex shapes and lower energy demand compared to forging (reviewed in [26][27][28] ). A majority of thixoforming studies in the literature have concentrated on conventional casting alloys, such as A356 and A357.…”

Section: Metal Matrix Nanocomposites (Mmncs)mentioning

confidence: 99%

Thixoforming of A356/SiC and A356/TiB2 Nanocomposites Fabricated by a Combination of Green Compact Nanoparticle Incorporation and Ultrasonic Treatment of the Melted Compact

Kandemir

Atkinson

Weston

et al. 2014

Metall Mater Trans A

View full text Add to dashboard Cite

Thixoforming is a type of semi-solid processing which is based on forming metals in the semisolid state rather than fully liquid or solid state. There have been no reports of the thixoforming of nanocomposites in the literature. The incorporation of ceramic nanoparticles into liquid metals is a challenging task for the fabrication of metal matrix nanocomposites due to their large surface-to-volume ratio and poor wettability. Previous research work by a number of workers has highlighted the challenges with the incorporation of nanoparticles into liquid aluminum alloy. In the present study, SiC and TiB 2 nanoparticles with an average diameter between 20 and 30 nm were firstly incorporated into green compacts by a powder forming route, and then the compacts were melted and treated ultrasonically. The microstructural studies reveal that the engulfment and relatively effective distribution of the nanoparticles into the melt were achieved. The hardness was considerably improved with only 0.8 wt pct addition of the nanoparticles. The nanocomposites were successfully thixoformed at a solid fraction between 0.65 and 0.70. The microstructures, hardness, and tensile mechanical properties of the thixoformed nanocomposites were investigated and compared with those of the as-received A356 and thixoformed A356 alloys. The tensile properties of the thixoformed nanocomposites were significantly enhanced compared to thixoformed A356 alloy without reinforcement, indicating the strengthening effects of the nanoparticles.

show abstract

Semisolid metal processing

Cited by 822 publications

References 93 publications

Improvement in Mechanical Properties of AZ91D Mg-Alloy through Thixomolding Process

Improvement in Mechanical Properties of AZ91D Mg-Alloy through Thixomolding Process

Effects of Mg and RE additions on the semi-solid microstructure of a zinc alloy ZA27

Thixoforming of A356/SiC and A356/TiB2 Nanocomposites Fabricated by a Combination of Green Compact Nanoparticle Incorporation and Ultrasonic Treatment of the Melted Compact

Contact Info

Product

Resources

About