Pressure infiltration of boron nitride preforms with molten aluminum for low density heat sink materials

Composite Materials Infiltrated by Aluminium Alloys Based on Porous Skeletons from Alumina, Mullite and Titanium Produced by Powder Metallurgy Techniques

“…The technologies of their manufacturing processes are one of the most sharply evolving fields of materials engineering. In order to address the expectations of the market, it is substantiated to undertake measures aimed at developing alternative methods of light metal matrix composites, mainly aluminium and magnesium alloys [12][13][14][15][16][17][18][19][20][21][22]. Considering a high melting point, low density and good corrosion resistance of ceramics, the fibre-reinforced or particle-reinforced composites deriving from such ceramics are of special importance here.…”

“…Considering a high melting point, low density and good corrosion resistance of ceramics, the fibre-reinforced or particle-reinforced composites deriving from such ceramics are of special importance here. Of special importance, here is also a quest for alternative materials for the commonly used reinforcements in the form of Al 2 O 3 fibres and particles [10,15,[23][24][25], SiC [6,13], made of boron [26], whiskers of Al 2 O 3 or SiC, B 4 C [27], BN [12] and TiC [6,28] particles, graphene [5] or carbon nanotubes, as well as intermetallic phases [29], and even of high-melting metals and their alloys [30,31]. In the case of aluminium alloy matrix composites, the name of the matrix element is often provided directly in the name or abbreviation of such a composite, for example, aluminium matrix composites (AlMCs).…”

“…If halloysite is heated at temperature above 980°C, structural transformation of halloysite into mullite is seen according to the simplified formula [75]: [12,76]. A possibility to use mullite for this task was a reason why attempts were undertaken to apply the nanotubes obtained from halloysite, in which transformation will take place-during thermal processes-into mullite.…”

Mechanical Properties of the PcBN-Alcomposites are Improved by Pressure Infiltration

“…Itwas simple, but the choice ofthe volume of bind(Al) was troublesome and PAC'shomogeneity is so poor.There were residualAlinside of PACunder normal circumstances and thecBN-Al inadequatemixingby this method,that the residual Al and the inadequate mixingcan impact PAC's mechanical properties.In this work, Al and cBN was divided into three layers with cBN layer sandwiched in two layers of Al. Allayers wouldbe infiltrated into thecBN layer when they were melted at high temperature.Thus,the residual Al would be get rid from PAC along with the outside parcel and duing to the pressure gradient, Al would melted very uniformly ;so contributed tothe improvementof PAC's mechanical properties.Li et al studied on PAC by PI [15]in 2012, they only paid attention to the thermal conductivity butnoresearch on the effects of PI to PAC in mechanical properties.…”