Effects of ZrO2 on Zinc Crystalline Glaze

Zinc Crystal Glaze has its limits in practical use of commercial glaze due to the sensitive firing schedule. In order to overcome these limits, and to improve the practical usage, this study is aimed to develop a stable zinc crystalline glaze. This study altered the quantity of nuclear formation of zinc crystal glaze in order to control the willemite (Zn2SiO4) formation in the glaze. The addition of ZrO2 to zinc crystal glaze influences the quantity of nuclear formation and its preservation; thus ZrO2 was used to control the optimal firing temperature and the size of the crystal formation in the glaze to find a zinc crystal glaze capable of withstanding various ranges of temperatures.

Phosphanimin- und Phosphaniminato-Komplexe des Zinks. Kristallstrukturen von [ZnCl2(Me3SiNP(CH2)4CMe3)]2, [ZnI2(Me3SiNPEt3)]2, [ZnI2{Me2Si(NPEt3)2}] und [ZnBr(NPMe3)]4· CH2Cl2/ Phosphaneimine and Phosphoraneiminato Complexes of Zinc. Crystal Structures of [ZnCl2(Me3SiNP(CH2)4CMe3)]2, [ZnI2(Me3SiNPEt3)]2, [Znl2{Me2Si(NPEt3)2}], and [ZnBr(NPMe3)]4· CH2Cl2

The donor-acceptor complexes [ZnCl2(Me3SiNP(CH2)4CMe3)]2 (1)and [ZnI2(Me3SiNPEt3)]2 (2) have been prepared from the zinc dihalides and the corresponding silylated phosphaneimines in CH2Cl2. Thermolysis of 2 leads to the formation of [ZnI2(Me2Si(NPEt3)2)] (3). Znl2 and ZnBr2 react with the silylated phosphaneimines Me3SiNPR3(R = Me, Et) in the presence of NaF at elavated temperatures to give the phosphoraneiminato complexes [ZnI(NPEt3)]4 (4), [ZnBr(NPMe3)]4 (5) and [ZnBr(NPEt3)]4 (6), respectively, which according to the IR spectra and to a crystal structure determination of 5 form heterocubane structures. The corresponding reactions with the more bulky phosphaneimine Me3SiNP(CH2)4CMe3 do not lead to a phosphoraneiminato complex of zinc. 1: Space group P21/n, Z = 2; lattice dimensions at -60 °C: a = 903.3(2), b = 1217.9(3), c = 1591.6(2) pm, β = 93.94(1)°, R = 0.031. 2: Space group P21/n, Z = 2; lattice dimensions at -70°C: a = 947.9(2), b = 1219.2(2), c - 1527.1(2) pm, 0 = 91.17(1)°, β = 0.045. 1 and 2 form centrosymmetric dimeric molecules via Zn2X2 bridges (X = Cl, I); bond lengths Zn-N = 198.7(2) pm (1) and 199.0(6) pm (2). 3: Space group P412121 Z = 8; lattice dimensions at -90°C: a = b = 965.4(1), c = 2796.9(2) pm, R = 0.019.3 forms monomeric molecules with the Me2Si(NPEt3)2 ligand as chelating agent to give a planar ZnN2Si four-membered ring with Zn-N distances of 207.0(2) pm. 5: Space group P42/nmc, Z = 2; lattice dimensions at -70°C: a = b = 1146.9(6), c = 1437.9(7) pm, R = 0.060.

A Metallurgical Approach to the Cracking Resistance of Hot-Dip Galvanized Zinc Coatings

The texture of zinc coatings influences to a large extent their formability, due to the anisotropic properties of zinc. The (0002) basal plane is the easiest slip plane in zinc crystal. Its inclination to the deformation axis and direction directly influences the deformation behaviour. This work deals with the effect of the texture and microstructure on the cracking behaviour of zinc coatings. For this purpose, twelve different commercial hot-dip zinc coatings have been studied.