Nanocrystalline Al3Ni2 alloy with high hardness produced by mechanical alloying and high-pressure hot-pressing consolidation

Nanocrystalline Al 5 Fe 2 intermetallic and Al 5 Fe 2 –Al composites manufactured by high-pressure consolidation of milled powders

“…However, in the case of composite powders containing Al, application of such high temperature can cause reaction between composite constituents [31,32]. For example, the temperature of 1000 C was appropriate for highpressure consolidation of an Al 3 Ni 2 intermetallic with nanocrystalline structure preserved [33], but too high for consolidation of an Al 3 Ni 2 eAl composite powder without reaction between constituents [31]. Hence, the applied hot-pressing temperature should be high, but not enough to cause undesired reactions.…”

Compound Formation and Microstructure of As-Cast High Entropy Aluminums

“…Table 5 shows the mean microhardness value with the standard deviation and the density of the studied alloys. The standard deviation of the microhardness is very large in HEAl-1, because Al 3 Ni 2 which is the main phase (Region 1 in Figure 2a), has very high hardness of 887-898 Hv [32] comparing with the rest of phases in the microstructure. According to the Tabor relation [33], the Vickers hardness divided by 3 should approximate the yield strength.…”

Nanocrystalline Ni3Al-based alloys obtained by recycling of aluminium scraps via mechanical alloying and consolidation

“…The increase of grain size is a result of the application of high temperature during the consolidation. On the other hand, the use of a high pressure and reduction of the exposure time in the high temperature prevents the excessive growth of grains which are still in the nanometer range [9][10][11]. This method of compaction of the milled powders was successfully used to obtain bulk nanocrystalline alloys from Fe-Al powders [9,[21][22][23].…”

“…The compaction of nanocrystalline powders is a very difficult process because it requires the application of high temperature which may cause the grain growth in the material. However, the simultaneous application of high pressure could inhibit the grain coarsening tendency [9][10][11].…”