ASTM_F_2024_-_10.pdf

Designation:F202410Standard Practice forX-ray Diffraction Determination of Phase Content of Plasma-Sprayed Hydroxyapatite Coatings1This standard is issued under the fixed designation F2024;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This practice is for the determination,by the ReferenceIntensity Ratio External Standard Method,of the percent byweight of the crystalline phases,hydroxyapatite(HA),beta-(whitlockite)tricalcium phosphate(b-TCP),and calcium oxide(CaO)in coatings deposited upon metallic substrates byplasma-spraying hydroxyapatite.1.2 A major component in plasma-sprayed HA coatingsother than HA is expected to be amorphous calcium phosphate(ACP).Crystalline components other than HA that may bepresent include alpha-and beta-(whitlockite)tricalciumphosphates,tetracalcium phosphate(TTCP),calcium oxide,and calcium pyrophosphates.Quantification of the minorcrystalline components has proven to be very unreliable due toextreme overlap and confounding of X-ray diffraction peaks.Therefore,this practice addresses the quantification of onlyHA,b-TCP,and CaO.1.3 This practice was developed for plasma-sprayed HAcoatings with HA contents of at least 50%of the total coating.It is recognized that the analysis of the crystalline componentsuses diffraction from regions of the pattern that also includes asmall contribution from the amorphous component.However,within the limits of applicability of this practice,the effect ofsuch interference is believed to be negligible.1.4 The coating analyzed shall be produced and processedunder equivalent manufacturing conditions to that on thedevice of interest.1.5 This practice requires the use of monochromated copperKa radiation and flat samples.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions:2.1.1 crystalline phases:Chemical and MineralNamesFormulaPDF Card No.2whitlockitebeta-tricalcium phosphateb-Ca3(PO4)29-169calcium phosphatealpha-tricalcium phosphatea-Ca3(PO4)29-348limecalcium oxideCaO37-1497hydroxyapatite(hydroxylapatite)Ca5(PO4)3OH9-4322.2 plasma-sprayed hydroxyapatite coatinga coating,consisting of at least 50%hydroxyapatite by weight,preparedby plasma-spraying hydroxyapatite on a substrate.3.Significance and Use3.1 Calcium phosphate coatings have been shown in animaland clinical studies to be biocompatible and to enhance theearly attachment of bone to implant surfaces(see Refs.1-5)33.2 It is believed that the form of calcium phosphateceramic and its purity with respect to secondary crystallinephases and amorphous material have an effect on its physical,mechanical,and biological properties.However,no definitivestudies of effects on biological properties have been completed.To achieve reproducible clinical results and to permit thedetermination of the effects of properties of the coating onbiological performance,it is essential that the properties ofboth clinical and experimental materials be well-characterizedand consistent.1This practice is under the jurisdiction ofASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.13 on Ceramic Materials.Current edition approved June 1,2010.Published June 2010.Originallyapproved in 2000.Last previous edition approved in 2000 as F202400 which waswithdrawn in January 2009 and reinstated in June 2010.DOI:10.1520/F202410.2Joint Committee on Powder Diffraction Standards,Swarthmore,PA.3The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.3 This practice provides procedures for determination ofthe percentage by weight of the crystalline phases identified ashydroxyapatite,b-TCP and CaO in plasma-sprayed hydroxy-apatite coatings.4.Quantitative Phase Analysis by the External StandardTechnique4.1 The external standard technique allows the determina-tion of weight fractions of individual phases in a mixturecontaining an amorphous fraction by comparison of the inte-grated intensity of one or more peaks from the phase(s)ofinterest to the external standard under identical instrumentalconditions(6).The sample analyzed may be a solid such as aplasma-sprayed coating or may be a powder.The massabsorption coefficients of the sample and standard must beknown.4.2 The weight fraction of the analyte phase in the