DSC study of the deposition reactions of zinc pack coatings up to 550°C

被引：24

作者：

Pistofidis, N.

Vourlias, G.

Chaliampalias, D.

Pavlidou, E.

Chrissafis, K.

Stergioudis, G.

Polychroniadis, E. K. ^{[1
]}

Tsipaa, D.

机构：

[1] Aristotle Univ Thessaloniki, Dept Phys, GR-54006 Thessaloniki, Greece

[2] Aristotle Univ Thessaloniki, Dept Mech Engn, GR-54006 Thessaloniki, Greece

来源：

JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY | 2006年 / 84卷 / 01期

关键词：

chemical vapor deposition; DSC characterization; metallic coatings; pack cementation;

D O I：

10.1007/s10973-005-7196-4

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

Zn pack coating formation takes place in three steps as differential scanning calorimetry shows. The initial step (at 193.9 degrees C) is endothermic and involves the transformation of alpha-N-H4Cl to beta-NH4Cl and the NH4Cl decomposition to NH3 and HCl. During the second step (at 248.6 degrees C), which is exothermic, Zn2+ salts are formed and most probably ZnCl2. Finally at 264.1 degrees C (endothermic reaction) it seems that ZnCl2 is decomposed to form Zn that is deposited on the ferrous substrate. The as-cast Zn diffuses in the iron substrate forming the gamma and delta phase of the Fe-Zn phase diagram. Al2O3 is not involved in the above-mentioned mechanism and acts only as filler.

引用

页码：191 / 194

页数：4

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