Experimental Diffusion Research on BCC Ti-Mn Binary and Ti-Al‐Mn Ternary Alloys

Abstract

Interdiffusion in the BCC phase of the Ti-Mn binary and Ti-Al-Mn ternary systems was investigated between 1273 and 1473 K by applying the diffusion-couple technique. The local chemical compositions within the interdiffusion zone of the diffusion couples were acquired by electron probe microanalysis (EPMA). The raw composition profiles were then analytically represented by the error function expansion, which allow the ternary inter-and impurity diffusivities to be appropriately extracted by the Whittle-Green and generalized Hall methods, respectively. It was demonstrated that, all four diffusion coefficientsD k ij

Diffusion Research in BCC Ti-Al-Zr Ternary Alloys

“…ZrZr was noticed to decrease with the increase of Al and Zr contents at 1273 K (1000°C) while presents an increasing trend at 1473 K (1200°C). These distinct variations of the main interdiffusion coefficients with respect to compositions are consistent with the interdiffusion in the BCC Ti-Zr [14] and Ti-Mn binary alloys, [19] which are very likely due to the thermodynamic contribution (via thermodynamic factor) varying with the composition in the ternary system to the interdiffusion coefficients. Ti À AlÞ Ã 1273K ð Þ¼4:02: The findings obviously clarify that the temperature dependence is noticeable.…”

“…A systematic comparison of the average main interdiffusion coefficients at 1473 K (1200°C) in ten Ti-Al-X (Ni, [29] Co, [30] Fe, [31] Mn, [19] Zr, Cr, [32] Sn, [18] V, [33] Nb, [27] Mo [24] ) ternary systems is presented in Table 5. The diffusion rate of Zr is one order of magnitude smaller than the fast diffusers (i.e.…”

“…Figure 1 presents the backscattered electron (BSE) image of diffusion couple A7 at 1273 K (1000°C) for 48 h and the composition profiles of Al and Zr obtained by the EPMA measurements. To avoid the point-to-point fluctuation of the experimental data and the errors introduced during the fitting or smoothing, the error function expansion (ERFEX) [16][17][18][19] was used to represent the composition profiles acquired by EPMA with analytical form:…”

THE The ternary system Hf–Re–Al at 1000 °C

“…If we compare the Hf-Re-Al system with previously studied T IV -T VII -M III systems, we can see that they differ both in the nature of the phase fields and in the number and types of ternary compounds that exist in the systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. In most of the systems involving boron, compounds are either absent or a single compound is formed.…”

“…Ternary systems involving d-elements of groups IV and VII and p-elements of group III of the periodic table have been studied for more than 50 years. Isothermal sections of the phase diagrams have been constructed for the Ti-Mn-B [1], Zr-Mn-B [2], Ti-Re-B [3], Hf-Re-B [4], Ti-Mn-Al [5][6][7][8], Ti-Mn-Ga [9], Zr-Mn-Ga [9,10],…”