Effects of Impurities on the Melting Curve of the Aluminium Fized Point
This work describes the influences of trace impurities on the freezing and melting temperatures of high purity(99.9999%) aluminium (660.323℃), specified for use in the International Temperature Scale of 1990 (ITS-90)1. The offsets and shapes of melting and freezing plateaus of high purity aluminium are investigated as a function of very low level dopants (mass fraction of ～1-20 parts per million by weight (ppmW)) of copper, silicon, and titanium pure metals. The freezing curves of the aluminium fixed-point decreased and increased in line with expectations derived from interpolation of previous experimentst2 as increased amounts of impurities were introduced; the rates are as follows: Cu0.43; Si -0.85; and Ti+3.2 in units of mK/ppmW.
Metrology Aluminium fized point ITS-90 Temperature measurement Impurity doping
David I Head Patchariya Petchpong Joe Y.H.Au
National Physical Laboratory, Hampton Road, Teddington, Middlesex TW11 0LW, UK Advanced Manufacturing and Enterprise Engineering Group, Bmnel University, Uxbridge, Middlesex UB8 3
国际会议
2008年国际温度与热物性测量会议(TEMP BEIJING 2008)
北京
英文
90-94
2008-10-20（万方平台首次上网日期，不代表论文的发表时间）