To　improve　the　strength　and　hardness,　Al-containing　FeCoCrNiMn　high-entropy　alloys　(HEAs)　were　fabricated　by　mechanical　alloying　(MA)　and　hot-pressed　sintering.　The　effects　of　Al　concentration　on　the　microstructure　and　mechanical　properties　of　the　alloys　were　examined.　It　was　found　that　the　Al-containing　alloys　consisted　of　the　matrix　fcc　or　fcc　+　bcc　duplex　solid　solution　phases　and　a　small　quantity　of　M7C3　+　M23C6　(where　M　=　Cr,　Mn,　Fe)　carbides　and　Al2O3　phases.　A　high　Al　concentration　induced　bcc　precipitates　in　the　alloys,　and　with　the　increase　of　Al　concentration,　the　crystalline　structure　of　the　matrix　solid　solution　phase　changed　from　fcc　to　bcc.　The　addition　of　Al　obviously　strengthened　the　alloys,　especially　the　alloys　that　contained　fcc　+　bcc　duplex　solid　solution　phases.　For　example,　the　yield　strength,　compressive　strength　and　hardness　of　alloy　FeCoCrNiMnAl0.7　reached　as　high　as　2230　MPa,　2552　MPa　and　622　HV,　respectively.　The　high　strength/hardness　was　attributed　mainly　to　the　finer　grains　and　the　bcc　precipitation.　(C)　2018　Elsevier　B.V.　All　rights　reserved.