Thermal expansion of Fe-TM-B (TM=transition metal) bulk amorphous forming alloys

Abstract

In order to clarify the potential of bulk amorphous alloys as a new class of structural materials with high dimensional stability, the thermal expansion and magnetic properties of amorphous Fe56Co7Ni7Zr10B20 doped with Cr have been investigated. Both the magnetic moment and the Curie point of amorphous Fe56Co7Ni7Zr10B20 were suppressed by Cr addition. The effect of Cr on the magnetic moment was well described by assuming a reduction of 4μB∕Cr atom. It was found that the Curie temperature can be controlled by Cr content over a wide range of 200K in the vicinity of room temperature. Although Invar characteristics were absent from the thermal expansion curves, amorphous Fe56Co7Ni7Zr10B20 doped with 1at.% Cr was found to exhibit a small coefficient of thermal expansion comparable to Kovar alloys, indicating that bulk amorphous alloys may have a potential for commercial low expansion materials.

Designing in situ and ex situ bulk metallic glass composites via spark plasma sintering in the super cooled liquid state

“…The SAM2X5 structure appears to be negligibly affected by W additions so that the thermal expansion coefficient of the SAM2X5-630 composite can be applied to analysis of the ex situ composites. The measured linear thermal expansion coefficient of the SAM2X5-630 composite was 6.6 K -1 , which is similar to other Fe-based amorphous alloys [35]. The linear thermal expansion coefficient of W is 4.6 K -1 [115].…”

“…Fe-based metallic glasses and composites are of interest because they are less expensive than many other amorphous alloys [26], have yield strengths as high as 4 GPa [27,28], excellent magnetic properties [29][30][31][32][33][34], low coefficients of thermal expansion [35], excellent corrosion resistance [36][37][38][39][40][41][42], and can be used in a variety of applications [6,43,44]. Most Fe-based metallic glasses are based on an "80-20" rule, with approximately 80 at% metals (M) and 20 at% semimetals (S) and/or nonmetals (N), and is based on short range order that consists of distorted clusters with M:(N+S) ratios close to 80:20 [45].…”

Invar effects of (Fe71.2B24Y4.8)96Nb4 alloy in different structural states

“…In summary, the unusual thermal behaviors prove the existence of clear Invar effects in ͑Fe 71.2 B 24 Y 4.8 ͒ 96 Nb 4 BMG. 8 An interesting observation from Fig. 1͑d͒ is that there is no obvious Invar abnormality in the master alloy with coarse grains.…”

“…7 This paper reports the observation of the clear Invar effects of ͑Fe 71.2 B 24 Y 4.8 ͒ 96 Nb 4 BMG. 8 The Invar effects of ͑Fe 71.2 B 24 Y 4.8 ͒ 96 Nb 4 alloys in different structural states are also investigated.…”

Low expansion in [(Fe0.9Co0.1)0.72B0.24Nb0.04]95.5Y4.5 bulk metallic glass

“…In recent years, Fe-rich bulk metallic glasses (BMGs) were discovered as a new class of multicomponent alloys with high glass forming ability and excellent engineering properties [12][13][14][15][16][17][18][19], which are helpful to study the structure disorder effect on thermal expansion. While little work has been done on the thermal expansion of Fe-based amorphous alloys [20][21][22]. In this paper, the temperaturedependent thermal expansion, magnetization, and specific heat C p of the as-cast and annealed [(Fe 0.9 Co 0.1 ) 0.72 B 0.24 Nb 0.04 ] 95.5 Y 4.5 BMG is studied.…”