ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
This study aims to explore phase transformation in plasma-sprayed hydroxyapatite (HA) + 10 wt% ZrO2–8-mol%-Y2O3composite coating, using separately prepared HA and ZrO2–8-mol%-Y2O3coatings as a control. Changes in the phase and chemistry of the coatings are characterized by X-ray diffractometry, with lattice-constant measurement (Cohen's method), and by transmission electron microscopy. Experimental results show evidence of diffusion, in the liquid state, of calcium ions from the HA matrix into the ZrO2. This behavior causes the formation of the following structural features in the composite coating: (i) a CaO-doped ZrO2solid solution (ZrO2–7.7 mol% Y2O3–4.4 mol% CaO); (ii) a mixture of ZrO2and CaZrO3having a crystal-orientation relationship; (iii) an amorphous phase containing elements of calcium, phosphorus, zirconium, and yttrium; and (iv) a remaining CaO-poor HA matrix (Ca10−x(HPO4)x(PO4)6−x(OH)2−x; x= 0.06). Rationales for the greatly decreased impurity phases of CaO and Ca4P2O9found in the composite coating are discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.2002.tb00147.x
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