Thermoelectric Properties of Titanium with Special Reference to the Allotropic Transformation

Abstract

A differential method for determining the thermoelectric power of titanium/platinum thermocouples is described. The results of the differential measurements are compared with data obtained in direct e.m.f. versus temperature determinations. From the thermoelectric power results, the temperature dependency of the following properties has been deduced : (a) the Peltier coefficient of the titanium/platinum couple ; (b) the difference between the Thomson coefficients of titanium and platinum ; (c) the absolute thermoelectric power of titanium. It is shown that abrupt changes in thermoelectric properties accompany the α-β transformation in refined titanium, the transition temperature range being 883 � 1 to 887 � 2 �C. In a commercial grade of titanium, the transformation occurs over the range 868 to 970 �C. Some effects due to preferred orientation and the elimination thereof are also reported.

Titanium-uranium system in the region 0 to 30 atomic percent of titanium

“…Th e gamma-beta transformation of uranium was found to have been lowered by increasing titanium addi tions, becoming constant at 71 8° C in the vicinity of 5 atomic percent of titaI1ium. The beta-alpha transformation of the alloys appeared consistently at 667° C. Worner [4] showed that r ehea ting of titaniLlpl und er pressure of 10-5 to 5 X 10-5 mm of m er cury elevated andbl'oadened the transformation range of titanium, the influence being attributed to oxygen and nitrogen pickup. It is quite probable that for this reason the purity of titanium used in the alloys for this investigation appeared to have exer ted no appreciable influ ence on the observed temperatures of transformation of uranium, but it was noted th at there were sharper arrests on the cooling curves for alloys con taining titanium produced by the iodide m ethod .…”

Dental cements, direct filling resins, composite and adhesive restorative materials: A resume

“…Data from the most extensive investigation [20] of the properties of these cements are given in Table 111. The values were derived by the methods described in the A.D.A.…”