Fluid-Structural Interaction Analysis of the MMC-Thixoforging Process

2006 ◽  
Vol 116-117 ◽  
pp. 591-595
Author(s):  
Mathias Liewald ◽  
Peter Unseld ◽  
M. Schneider
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Interaction Analysis ◽  
Rheological Behaviour ◽  
Woven Fabrics ◽  
Special Focus ◽  
Matrix Composites ◽  
Matrix Metal ◽  
Infiltration Process ◽  
Aerospace Applications

High mechanical properties in combination with low density are key features for lightweight constructions in automotive and aerospace applications. The combination between the innovative thixoforging process and the potential of fibre or particle strengthened composites with metallic matrices (MMCs) provides an efficient manufacturing process of structural components with continuous or gradient reinforcements. The scope of the Center of Competence for Casting and Thixoforging Stuttgart (CCT) contains new semi-solid manufacturing methods for metal matrix composites which have been developed and applied for patent pending. While previous research projects were focussed on fabrication of continuous fibre reinforced metal matrix composites, the local reinforcement insertion, located in the center of high force and torsion load zones, is going to be the next evolution step of the CCT research team. Therefore it is essential to verify, to simulate and to reproduce the process during infiltration of the semi-sold matrix metal into the textile layer experimentally. This paper illustrates investigations regarding the infiltration process of the thixotropic cast-alloys AlSi7Mg0.3 (A365) into laminated fibre woven fabrics by computational fluid dynamics and fluid-structure interaction analysis, taking account into specific manufacturing technology, the rheological behaviour of the alloy with special focus on infiltration behavior.

scholarly journals Wettability in Metal Matrix Composites

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1034
Author(s):  
Massoud Malaki ◽  
Alireza Fadaei Tehrani ◽  
Behzad Niroumand ◽  
Manoj Gupta
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Aluminum Matrix ◽  
Interfacial Strength ◽  
High Strength ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Metal Matrix Nanocomposites ◽  
Aerospace Applications ◽  
Matrix Nanocomposites

Metal matrix composites (MMCs) have been developed in response to the enormous demand for special industrial materials and structures for automotive and aerospace applications, wherein both high-strength and light weight are simultaneously required. The most common, inexpensive route to fabricate MMCs or metal matrix nanocomposites (MMNCs) is based on casting, wherein reinforcements like nanoceramics, -carbides, -nitrides, elements or carbon allotropes are added to molten metal matrices; however, most of the mentioned reinforcements, especially those with nanosized reinforcing particles, have usually poor wettability with serious drawbacks like particle agglomerations and therefore diminished mechanical strength is almost always expected. Many research efforts have been made to enhance the affinity between the mating surfaces. The aim in this paper is to critically review and comprehensively discuss those approaches/routes commonly employed to boost wetting conditions at reinforcement-matrix interfaces. Particular attention is paid to aluminum matrix composites owing to the interest in lightweight materials and the need to enhance the mechanical properties like strength, wear, or creep resistance. It is believed that effective treatment(s) may enormously affect the wetting and interfacial strength.

Influence of Distinct Manufacturing Processes on the Microstructure of Ni-Based Metal Matrix Composites Submitted to Long Thermal Exposure

2019 ◽  
Vol 809 ◽  
pp. 79-86
Author(s):  
Georges Lemos ◽  
Márcio C. Fredel ◽  
Florian Pyczak ◽  
Ulrich Tetzlaff
Keyword(s):  
Metal Matrix Composites ◽  
High Temperatures ◽  
Metal Matrix ◽  
Thermal Exposure ◽  
High Energy ◽  
Matrix Composites ◽  
Microstructural Stability ◽  
Aerospace Applications ◽  
Plasma Sintering ◽  
Energy Processes

Metal Matrix Composites (MMCs) are known for their remarkable properties, by combining materials from different classes. Ni-based MMCs are a promising group of heat-resistant materials, targeting aerospace applications. A discontinuously reinforced Inconel X-750/TiC 15 vol.% MMC was proposed for use in lighter, creep resistant turbine elements, with the aim to endure service temperatures up to 1073 K (800 °C). However, their microstructural stability at high temperatures for long periods of time remained to be further investigated. To address this need, specimens were produced by both conventional hot pressing and spark plasma sintering, using powders milled by low and high energy processes, followed by long isothermal aging. The treatments were conducted at 973 and 1073 K, for times between 50 and 1000 hours. The resulting samples were investigated with XRD and EDS techniques for phase analysis. In addition, measurements of hardness were made to monitor changes in mechanical behavior. It was found that, for each different manufacturing process, the amount, distribution and size of γ’ and other precipitates notably vary during the overaging process. Consequently, the amount of elements kept in solid solution also shifted with time. Furthermore, the study shows how distinct initial microstructures, resulting from diverse fabrication processes, differently impact the microstructural stability over long times of exposure to high temperatures.

Diamond/Al metal matrix composites formed by the pressureless metal infiltration process

1993 ◽  
Vol 8 (5) ◽  
pp. 1169-1173 ◽  
Author(s):  
William B. Johnson ◽  
B. Sonuparlak
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Coefficient Of Thermal Expansion ◽  
Matrix Composites ◽  
Infiltration Process ◽  
Point Bend ◽  
Aluminum Metal Matrix Composites ◽  
Metal Infiltration

Diamond particles are unique fillers for metal matrix composites because of their extremely high modulus, high thermal conductivity, and low coefficient of thermal expansion. Diamond reinforced aluminum metal matrix composites were prepared using a pressureless metal infiltration process. The diamond particulates are coated with SiC prior to infiltration to prevent the formation of Al4C3, which is a product of the reaction between aluminum and diamond. The measured thermal conductivity of these initial diamond/Al metal matrix composites is as high as 259 W/m-K. The effects of coating thickness on the physical properties of the diamond/Al metal matrix composite, including Young's modulus, 4-point bend strength, coefficient of thermal expansion, and thermal conductivity, are presented.

Wear Characteristics of Particulate Reinforced Metal Matrix Composites Fabricated by a Pressureless Metal Infiltration Process

2006 ◽  
Vol 510-511 ◽  
pp. 234-237 ◽  
Author(s):  
Jae Dong Kim ◽  
Hyung Jin Kim ◽  
Sung Wi Koh
Keyword(s):  
Wear Resistance ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Volume Fraction ◽  
Wear Loss ◽  
Matrix Composites ◽  
Slow Speed ◽  
Infiltration Process ◽  
Sliding Speed ◽  
Metal Infiltration

The effect of size and volume fraction of ceramic particles with sliding speed on the wear properties were investigated for metal matrix composites fabricated by a pressureless metal infiltration process. The particulate metal matrix composites exhibited about 5.5 - 6 times greater wear resistance compared with AC8A alloys at high sliding speed, and by increasing the particle size and decreasing the volume fraction the wear resistance improved. The wear resistance of the metal matrix composites and AC8A alloy represented different aspects: the wear loss of the AC8A alloy increased with sliding speed linearly, whereas, the metal matrix composites displayed more wear loss than the AC8A alloy in the slow-speed region. However, a transition point of wear loss was found in the middle-speed region, which shows the minimum wear loss. Furthermore, wear loss in the high-speed region exhibited almost the same value as the slow-speed region. In terms of wear mechanism, the metal matrix composites showed abrasive wear at a slow to high sliding speed generally. However, the AC8A alloy showed abrasive wear at low sliding speed and adhesive and melt wear at a high sliding speed.

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