Powder Processing of Metal Matrix Composites

Ionitã, Gheorghe

doi:10.1016/b0-08-042993-9/00026-7

Cited by 9 publications

(6 citation statements)

References 50 publications

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“…This has also been verified in previous DSC studies of the Al-TiO 2 -C [8] and Al-TiO 2 [9] systems. After heating to 1040 C, TiAl 3 phase disappears completely.…”

supporting

confidence: 69%

Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Wang¹,

Liu

Bian

2004

Adv Eng Mater

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Particulate-reinforced in situ metal matrix composites (MMCs) possess excellent properties such as high specific strength and modulus, elevated-temperature resistance, but are low in fabrication costs. Thus, their production is of special interest in the advanced materials research field. [1±7] The in situ production of MMCs involves the formation of the reinforcing phases through direct chemical reactions in the metallic matrices. Ceramic TiC, TiB 2 , Al 2 O 3 , and SiC, etc. have been widely used as reinforcements for the in situ MMCs, especially aluminum matrix composites. [1±4] Recently, the systems of Al-TiO 2 -X, where X is boron, [5,6] B 2 O 3 , [5,7] or carbon, [8] have been investigated to prepare (TiB 2 +Al 2 O 3 ) or (TiC+Al 2 O 3 ) reinforced aluminum composites. The present work will report the reaction process in the Al-TiO 2 -CB 4 system and the successful synthesis of an Al/(TiC+TiB 2 +Al 2 O 3 ) composite through the in situ reaction of this system in molten aluminum. Figure 1 shows the DSC curve of the Al-TiO 2 -CB 4 pellet heated to 1300 C and followed by cooling. During heating, an endothermic peak with the maximum at 674.4 C, corresponding to the melting of Al, and two exothermic peaks which overlap each other between 862 and 1020 C, can be observed. It is clear from the presence of phases revealed on the XRD patterns of the as-milled powder and this heated pellet (Fig. 3) that the two exothermic peaks are related to reactions between the starting materials to form the desired TiB 2 , TiC and a-Al 2 O 3 phases. During the cooling process, only an exothermic peak associated with the solidification of Al is present, indicating that the new phases formed are thermodynamically stable at the temperature of as high as 1300 C. To determine reactions at the exothermic peaks in Figure 1, pellets were heated in the DSC at the same rate to 948 and 1040 C respectively (Fig. 2a,b), and then subjected to XRD analysis.Compared with that in Figure 1, however, the DSC curves ending at 948 C and 1040 C (Fig. 2a,b) do not clearly show the small exothermic peak at the beginning of the exothermic event. While on the curve in Figure 2c, which was repeated for further comparison, a small peak appears after the large one, contrasting with Figure 1. Comparing the four DSC curves suggests that the exothermic events between 860 and 1040 C may be regarded as an exothermic peak. The starting, ending and the maximum temperatures of the exothermic peak during each run of heating are slightly different too. All these differences might be attributed to different density of each pellet.In the XRD pattern of the pellet heated to 948 C, TiAl 3 as well as TiC, TiB 2 , and a-Al 2 O 3 , are apparently detected. The presence of TiAl 3 suggests that the following reduction reaction of TiO 2 occurs:This has also been verified in previous DSC studies of the solidification of Al melting of Al 618°C 674.4°C 958.0 °C 900.3°C DSC (mW/mg) Temperature(°C)Fig. 1. DSC trace of the 70.4 %Al-24 %TiO 2 -5.6 %CB 4 pellet heated to 1300 C and f...

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“…This has also been verified in previous DSC studies of the Al-TiO 2 -C [8] and Al-TiO 2 [9] systems. After heating to 1040 C, TiAl 3 phase disappears completely.…”

supporting

confidence: 69%

Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Wang¹,

Liu

Bian

2004

Adv Eng Mater

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“…Higher porosity leads to lower density because the voids occupy space that would otherwise be occupied by solid material. The correlation between density and porosity is generally inverse, meaning that as porosity increases, density decreases. , It disregards the presence of crystal lattice defects, assuming that materials are perfectly crystalline at the theoretical densities. However, considering the fact that this is not the case, the data were higher than the data obtained as a result of experimental studies.…”

Section: Resultsmentioning

confidence: 99%

Microstructural and Radioactive Shielding Analyses of Alumix-231 and Alumix-231 Reinforced with B₄C/SiC/Al₂O₃ Particles Produced through Hot Pressing

Gökmen,

Eslam Jamal Golzari,

Gürgen Avşar

et al. 2023

ACS Omega

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Al 2 O 3 , SiC, and B 4 C (10%) particle-reinforced Alumix-231 matrix composites and nonreinforced Alumix-231 blocks were produced by pressing under uniaxial pressure using the powder metallurgy method. The Archimedes density of the produced samples was analyzed using microstructures (SEM and EDS), powder size analysis, and theoretical (PSD software) and experimental methods (Co-60 and Cs-137 radiation sources). As a result of the theoretical and experimental calculations, the Alumix-231 + 10% B 4 C composite material showed the lowest shielding feature against γ radiation, while the Alumix-231 + 10% Al 2 O 3 composite material showed the highest shielding feature.

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“…We recently developed the nitridation-induced self-formed aluminum composite (NISFAC) process as a facile and innovative route to manufacturing Al matrix composites (AMCs) [1][2][3]. Whereas, previously, the limited wettability between the reinforcement and the Al matrix had to be overcome by the use of high-energy mechanical stirring (e.g., stir casting) [4][5][6][7][8][9][10], high-pressure infiltration of molten Al into a preform [11][12][13][14][15][16], or high-pressure consolidation of the powder mixture (powder metallurgy) [16][17][18][19][20][21], a key feature of the NISFAC process is its flexibility with respect to the selection of reinforcement regardless of the level of wettability [1][2][3]. Although the nitridation of aluminum has been investigated by a variety of in-situ techniques such as directed metal oxidation [22], pressureless metal infiltration [23], and reactive gas injection [24], etc., there have been limited studies on the nitridation-induced forming of aluminum matrix composites.…”

Section: Introductionmentioning

confidence: 99%

Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites—Part 2: Effect of Nitrogen Flow Rates and Processing Temperatures

et al. 2020

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The nitridation-induced self-formed aluminum matrix composite (NISFAC) process is based on the nitridation reaction, which can be significantly influenced by the characteristics of the starting materials (e.g., the chemical composition of the aluminum powder and the type, size, and volume fraction of the ceramic reinforcement) and the processing variables (e.g., process temperature and time, and flow rate of nitrogen gas). Since these variables do not independently affect the nitridation behavior, a systematic study is necessary to examine the combined effect of these variables upon nitridation. In this second part of our two-part report, we examine the effect of nitrogen flow rates and processing temperatures upon the degree of nitridation which, in turn, determines the amount of exothermic reaction and the amount of molten Al in the nitridation-induced self-formed aluminum matrix composite (NISFAC) process. When either the nitrogen flow rate or the set temperature was too low, high-quality composites were not obtained because the level of nitridation was insufficient to fill the powder voids with molten Al. Hence, since the filling of the voids in the powder bed by molten Al is essential to the NISFAC process, the conditions should be optimized by manipulating the nitrogen flow rate and processing temperature.

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Powder Processing of Metal Matrix Composites

Cited by 9 publications

References 50 publications

Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Microstructural and Radioactive Shielding Analyses of Alumix-231 and Alumix-231 Reinforced with B₄C/SiC/Al₂O₃ Particles Produced through Hot Pressing

Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites—Part 2: Effect of Nitrogen Flow Rates and Processing Temperatures

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Powder Processing of Metal Matrix Composites

Cited by 9 publications

References 50 publications

Reaction in the Al‐TiO2‐CB4 System and in Situ Synthesis of an Al/(TiC+TiB2+α‐Al2O3) Composite

Reaction in the Al‐TiO2‐CB4 System and in Situ Synthesis of an Al/(TiC+TiB2+α‐Al2O3) Composite

Microstructural and Radioactive Shielding Analyses of Alumix-231 and Alumix-231 Reinforced with B4C/SiC/Al2O3 Particles Produced through Hot Pressing

Effect of Material and Process Variables on Characteristics of Nitridation-Induced Self-Formed Aluminum Matrix Composites—Part 2: Effect of Nitrogen Flow Rates and Processing Temperatures

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Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Reaction in the Al‐TiO₂‐CB₄ System and in Situ Synthesis of an Al/(TiC+TiB₂+α‐Al₂O₃) Composite

Microstructural and Radioactive Shielding Analyses of Alumix-231 and Alumix-231 Reinforced with B₄C/SiC/Al₂O₃ Particles Produced through Hot Pressing