Role of Mg and Mg+Si as external dopants in production of pure Al–SiC metal matrix composites by pressureless infiltration

Abstract

Metal matrix composites have been produced by pressureless in®ltration of pure Al into Mg doped SiC preforms after 1 h at 900³C. Aluminium has been found to in®ltrate preforms containing between 2 and 14 wt-%Mg, however Al did not in®ltrate a preform containing 1 wt-%Mg. Preforms doped with 1 wt-%Mg and Si did result in in®ltration. Increasing the Mg content or increasing the Si content in the preform resulted in more extensive in®ltration. The effect of Mg and Mg mixed with Si on pressureless in®ltration of pure Al, microstructure of MMC as well as mechanical properties are discussed. Although the dopant was uniformly distributed throughout the preform microstructural analysis and hardness measurements indicate that the resultant composite may not be uniform due to in®ltration inwards from the edge to the centre of preform.MST/4558

Surface chemistry modification for elimination of hydrophilic Al4C3 in B4C/Al composites

“…Fig. 7c) illustrates formation of SiC and BN, according to reactions [16][17][18][19]. Moreover, Fig.…”

“…Such techniques include modification of the chemical composition of the matrix [9,17,27], control of the processing parameters [23], surface modification of the reinforcements [16] and additions of SiO 2 to the reinforcements [9,10,28]. Most of the works reported in the related literature have focused on preventing Al 4 C 3 formation during processing.…”

“…[16]. The pressureless infiltration route offers attractive features, including near-net-shape component fabrication, lower deformation and fracture risks as compared to the pressureassisted infiltration route, and cost-effective processing costs [9,10,17].…”

“…The hydrolysis reactions proposed in the literature occur according to Eqs. (2) and (3) [4,[9][10][11]17,[21][22][23][24][25][26].…”

PENGARUH SUHU PEMANASAN DAN WAKTU TAHAN TERHADAP KARAKTERISASI MATERIAL KOMPOSIT LOGAM AL/SiC HASIL INFILTRASI TANPA TEKANAN

“…Ada dua syarat yang harus dilakukan pada proses pembuatan komposit ini, yaitu harus terdapat kandungan magnesium di dalam aluminium dan kondisi atmosfer nitrogen dalam dapur. Semakin banyak gas nitrogen yang mengalir akan semakin membantu kinerja magnesium untuk membasahi dan akhirnya memudahkan aluminium untuk terinfiltrasi [6][7][8].…”