4501 NTERNATIONAL STANDARD TSO Hardmetals -- Determination of titanium -- Photometric peroxide method Metaux-durs -Determination du titane-Methode photometrique au peroxyde First edition - 1978-08-01 ISO 4501-1978 (E) UDC 621.762.661.665.2 : 546.82 :543.42 Ref. No. 1SO 4501-1978 (E) Descriptors:hardmetals,chemical analysis,determination of content,titanium,spectrophotometric analysis Price based on 3 pages Coovriaht International Oraanization for Standardizatior FOREWORD ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of devcloping International Standards is carried out through Iso technical committees. Every member body interested in a subject for which a technicat committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with iso, aiso take part in the work. Draft international Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard is0 4501 was developed by Technicail Committee ISO/Tc 119, Powder metallurgical materials and products, and was circulated to the member bodies in June 1977. It has been approved by the member bodies of the following countries : Australia Germany Spain Austria Italy Sweden Bulgaria Japan Turkey Canada Mexico United Kingdom Czechoslovakia Poland U.S.A. Egypt, Arab Rep. of Romania U.S.S.R. France South Africa, Rep. of Yugoslavia No member body expressed disapproval of the document. @International Organization for Standardization,1978. Printed in Switzerland ISO4501-1978 (E) INTERNATIONAL STANDARD Hardmetals -- Determination of titanium - Photometric peroxide method 1SCOPE 5.7 Sulphuric acid, p 1,84 g/ml. This International Standard specifies a photometric 5.8Sulphuric peroxide method for the determination of the titanium acid, p 1,54 g/ml (sulphuric acid, p 1,84 g/ml, dituted 1 + 1). content of carbides and hardmetals. 5.9 Hydrogen peroxide, 30 % (m/m). 2 FIELDOFAPPLICATION 5.10 Hydrofluoric acid, p 1,12 g/mi. This method is applicable to carbide and binder metal powder mixtures,free of 5.11 Nitric acid, p 1,40 g/ml. lubricant, all grades of presintered or sintered hardmetals, 6 APPARATUS with a titanium content exceeding 0,2 % (m/m). Ordinary laboratory apparatus and 6.1 Spectrophotometer or filter photometer. 3PRINCIPLE Formation of a yellow complex of pertitanic acid. Deter- mination of the absorbance of the complex. 7SAMPLEPREPARATION 7.1 The sample shall be crushed to a powder in a mortar made of a material which does not alter the sample 4INTERFERINGELEMENTS composition. The powder shall pass a 0,18 mm sieve. The effect of interfering elements which also form coloured complexes with hydrogen peroxide under the conditions 7.2 The analysis shall be carried out on two or three specified,for example vanadium and molybdenum,shall test portions. be taken into account. A correction can be applied if the contentisbelow5%(m/m)ofeach. 8PROCEDURE 5REAGENTS 8.1 Preparation During the analysis, use only reagents of recognized ana- Select the mass of the test portion, the volume of the lytical grade, and only distilled water or water of equivalent volumetric flask and the cell length in accordance with purity. table 1. TABLE 1 5.1 Ammonium hydrogen fluoride. Titanium Testportion Flask Cell length 5.2 Ammonium sulphate. content mass volume % (m/m) ml mm 5.3 Sodium disulphite. 0,2 to 4 0,2 250 20 5.4 High-purity titanium metal or titanium dioxide, 2 to 8 0,2 250 10 analysed for all impurities exceeding 0,01 % (m/m) each. 5 to 15 0,2 500 10 10 to 30 0,1 500 10 5.5 Citric acid solution, 30 % (m/m). NOTE- Approximately 17mg of titanium in 250 ml of final 5.6 Perchloric acid, p 1,54 or 1,67 g/ml. solution gives unit absorbance with a 10 mm cell. 1