Vol.5 No.1 2012
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Research paper : An analysis method for oxygen impurity in magnesium and its alloys (A. Tsuge et al.)−33−Synthesiology - English edition Vol.5 No.1 (2012) the domestic organization deliberating proposals for ISO standard. One of the authors reported the progress of our research as a member of the Analysis Committee of JMA from the early stage of development of the oxygen analysis method in FY 2006 to develop the analysis method satisfying the demands in industry. In FY 2007, a questionnaire survey was conducted on the demands of oxygen analysis among the member companies of JMA. As a result, 20 % of the companies said that the analysis method was “needed immediately,” and 50 % “needed in the future.” The survey indicated the strong demand for oxygen analysis method in industry, and a strong reason for us playing an important role in supporting the process of proposing and carrying out the R&D project.4.2 Preliminary activities at the ISO technical committee and cooperation with KoreaFor three years from the beginning of FY 2008, we conducted the R&D project for submitting the draft standard of oxygen impurity analysis, under ”Kijun Ninsho Kenkyu Kaihatsu Seido” of the Ministry of Economy, Trade and Industry (METI). During this R&D project, we started activities at the ISO technical committee ISO/TC79/SC5Note 3) for Mg in advance before the submission of draft. The activities are summarized in Table 4. First, in the meeting held in Tokyo May 2009, the basic concept of this analysis method was introduced as the “Future Proposal to SC5,” and the plan of the ISO standardization proposal using this method was announced. In the meeting held in Berlin May 2010, we reported the progress of the development including the sampling method and the comparison with the result of CPAA. At that meeting, there was a report from Korea that said that the analysis cannot be done well under our measuring conditions introduced in Tokyo 2009. There is a big Korean firm that engages in both the iron and steel manufacturing and Mg components production, and they have deep understanding of the IGF-IRA method frequently used in the iron and steel industry. In addition, major Mg products in Korea are basic materials such as plates rather than components with specific functions. Under these circumstances, they have high demand for quality assurance such as suppressing oxygen content. This seems to be the most likely reason why Korea showed strong interest in the oxygen analysis method and conducted additional testing voluntarily. Recently Korea has occupied a position as a Mg basic material supplier and is enhancing its influence in SC5. It was expected that forming a technological alliance with Korea would be advantageous for the prospective standardization proposal process. Fortunately, at that point we knew the fact that the “applied power – graphite crucible temperature” relationship depends on the device and/or its manufacturing year as mentioned in 3.3, enabling to point out the cause of the problem mentioned above and solution thereof. In February 2011, a mission from the JMA visited Korea and obtained information that Korea was able to obtain stable analysis value by conducting the temperature calibration we suggested and good agreement with the result of CPAA using their original samples. In the ISO/TC79/SC5 meeting in London May 2011, we reported the method for temperature calibration of the graphite crucible and our technological cooperation with Korea. The secretary of SC5 commented, “The new proposal is well considered and we welcome it.”The early indication of intention to propose a draft standard and giving update of the development status at the ISO technical committee provide a better atmosphere to have constructive discussions. We believe a good impression that the “standardization will go smoothly without major friction” was given to the secretariat and P member countries.Note 4) The draft of the analysis method including the calibration of the graphite crucible temperature was proposed at the ISO/TC79/SC5 on June 2011 after the deliberation by the Standardization Committee of the JMA,, and is currently on three-month ballot as a new work item proposal (NWIP).5 Future prospectIn most standardization of analysis and evaluation methods, they are standardized based on established ones and from time to time, if necessary, differences of measuring conditions are reconciled among countries involved in the standardization. Meanwhile our case is perceived as rare because, we started from the development of basics of our method and eventually led to the proposal of standard to disseminate the method to industry. The dissemination and wide use of the frontier technology for analysis and evaluation is a dream of the researchers and engineers who are involved in the development of the measurement analysis technology. We believe standardization is essential in disseminating the frontier technology.This analysis method is being applied as the product management technology for heat resistant and fire-retardant magnesium in the project of “Development of Heat Resistant Components of Power Train by Casting of Heat Resistant and Fire-retardant Magnesium” in “Senryakuteki Kiban Gijutu Kodoka Shien Jigyo” (Support Industry Project), METI. To solve the issue of rendering Mg fire retardant, which is a major problem in using the Mg in transportation machineries, an alloy doped with calcium has been developed by AIST.[7] In regard to the improvement of the heat resistance of Mg components to use at high temperature, it is widely known that the addition of rare earth elements or silicon is effective. However, all of these additive metals have high oxygen affinity and are accompanied with the increase in oxides in the alloys. Moreover, although casting is a cost-efficient method for the components manufacturing, the reuse of runner and head, which are wastes in the casting process, as feed stock for casting is essential to prevent cost increase. The reuse of the recycled material in casting

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