Formation and properties of Zr₄₈Nb₈Fe₈Cu₁₂Be₂₄ bulk metallic glass

Abstract

Zr/Nb-based bulk metallic glass (BMG) with a composition of Zr 48 Nb 8 Fe 8 Cu 12 Be 24 was formed in cylindrical shapes 8 mm in diameter by the quartz tube water quenching method. The formation and acoustic, thermal, mechanical, and elastic properties of the BMG were investigated. The BMG exhibited excellent glass-forming ability, high thermal stability, and excellent mechanical properties.

Influence of Casting Parameters on the Critical Casting Size of Bulk Metallic Glass

“…[1][2][3][4][5][6][7][8][9][10] When liquid metal is cooled in a metal mold, the heat flow is controlled by two major factors: the interfacial resistance at the mold-metal interface [30][31][32] and the thermal conductivity of both the casting and mold. [31] For regular diecasting of crystalline metals of thin sections, the thermal conductivity of the casting is often neglected or considered insignificant in cooling and solidification calculations.…”

“…[4] with Eq. [5] and solving this linear equation, the analysis of the system can be further simplified by the elimination of T S . [31] Hence, the total amount of heat transferred from the center of the casting to the mold set at T o is given by [31] Q ¼…”

“…These alloys form glasses from the melt at relatively low cooling rates (from 200°C/s to as low as 0.1°C/s) that lead to amorphous sample sizes as large as 100 mm. [1][2][3][4][5][6][7][8][9] The term bulk metallic glass (BMG) is generally given to those alloy systems that retain a completely amorphous structure for a casting of section greater than 1 mm in diameter. [8] The GFA of a metallic glass specifies its resistance to crystallization during casting.…”

“…[1][2][3][4][5][6][7][8][9][10] For example, Zr-, Pd-, Ln-, and Mg-based BMGs have R C values below~100°C/s and, hence, are considered as having high GFA. [1][2][3][4][5][6][7][8] Over the past 40 years, numerous parameters have been proposed for predicting the ease of glass formation and glass stability in these materials, with examples including the following: the reduced glass-transition temperature or Turnbull's principle T rg = T g /T l ; [11,12] the supercooled liquid interval DT X = T X À T g ; [6] c = T X /(T g + T l ); [13] c m = (2T X À T g )/T l ; [14] DT rg = (T X À T g )/(T l À T g ); [15] d = T X /(T l À T g ); [16] u = T rg (DT X /T g ) 0.143 ; [17] a = T X /T l ; [18] b = T X /T g + T g /T l ; [18] b I = T X 9 T g /(T l À T X ) 2 ; [19] and more recently x = T g /T X À 2T g /(T g + T l ), [20] where T X and T l are the onset crystallization temperature and liquidus temperature, respectively. In general, there is no single parameter that accurately correlates GFA to a specific parameter in all alloy systems, with trends often corresponding well in some systems but not as well in others.…”

Study of Glass Forming on Cu60.0Zr32.5Ti7.5 Alloy by Molecular Dynamics Simulation

“…It is well known that metallic glasses based on zirconium [5][6][7] , palladium 8,9 and rare earth [10][11][12] have high GFA, thus several alloys were proposed. However, these materials are relatively expensive.…”