Research for preparation and high hardness material of aluminium higher boride MgAlB22

2015 Fiscal Year Final Research Report

• Project/Area Number: 25420716
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Inorganic materials/Physical properties
• Research Institution: Kokushikan University
• Principal Investigator: Okada Shigeru 国士舘大学, 理工学部, 教授 (40191952)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: アルミニウムマグネシウム高ホウ化物 / アルミニウム自己フラックス法 / ビッカース微小硬さ / 低温磁化率

Outline of Final Research Achievements

MgAlB22 crystals were grown from Al-self flux in an Ar atmosphere. The raw materials used Mg metal, Mg salts, B and Al. The conditions for growing MgAlB22 were established using the starting mixtures of atomic ratio B/Mg = 2.0. The temperature of the furnace was raised to 1400℃, kept for 5 h and then cooled at a rate of 50℃/h. The crystals were selected under a microscope for the measurements of micro-hardness and magnetic susceptibility. Magnetic susceptibility of MgAlB22 was measured by using a SQUID magnetometer. The MgAlB22 crystals obtained from Mg or MgF2 and boron powders as starting materials of atomic ratio B/Mg = 2.0. The MgAlB22 crystals have well-developed {100} faces and the maximum dimensions of about 6.5 mm. The reagents used to prepare the solid solution (Mg1-xLEx)AlB22(LE = Li, Na, K) crystals were Mg metal, LE2B4O7, B and Al. The (Mg1-xLEx)AlB22 crystal was not obtained at the experiment. The value of microhardness of crystal was in the range of 25.4(0.6) GPa.

Free Research Field

工学