Ti3AlC2粉末中在流动空气里的氧化行为检测方案(热重分析仪)

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ANSOICeramicsExcellence in thermal analysis and calorimetry Oxidation behavior of Ti AIC， powders in flowing air Reference： Oxidation behavior of Ti AlC， powders in flowing air X.H. Wang and Y.C. Zhou.J.Mater. Chem. 2002，12，2781-2785 Introduction： The oxidation behavior of Ti AlC， powders has been investigated in air by meansof simultaneousTGA-DSC， XRD， Raman spectra， SEM， EDS and BET specific surfacemeasurement to understand the intrinsic oxidation behavior of this newly developed ternarycompound. Fig.1 Fig.2 Experimental Simultaneous TGA-DSC experimentsonTi AlC， powders were conducted on a SetsysEvolution TGA-DSC with Al，O， crucibles.Samples were analyzed at a scan rate of10°C/minfromambient temperature to1500℃ in a flowing air atmosphere (Fig.1).Then， to understand the role of the Al atomsin the oxidation resistance of Ti，AIC，， TiCpowders were also subiected to simultaneousTGA-DSC experimentsunder theesameexperimental conditions (Fig.2). Results Differences were noted between the oxidationbehavior of Ti AlC， and that of TiC owing tothe presence of Al in the ternary. It can beseen on Fig.1 (TiAIC，) that the shape of DSCcurve is consistent with that of DTG. Thisindicates that the change in mass gain rate(DTG signal) resulted from the correspondingreactions associated with exothermic effect(DSC signal). The DTG and DSC curves weredivided into two parts by an apparent gapbetween650 and 850°C. The totalmasSincrease between 400℃cand1120℃suggests thatthestarting oxidationandcomplete oxidation temperatures of Ti3AlC2were 400 and 1120C respectively. Temperature (℃) Fig. 2 shows the simultaneous TGA-DTG-DSCcurves for TiC to compare the oxidationresistance of Ti，AlC， with that of TiC. AsTi，AlC，， TiC sample have a DSC curve in goodagreement with that of DTG curve. However，onlyaCobviousmass Increaseoccurredbetween350 and 1000°C， without a slowincrease of mass gain at 650-850°C. The twotypical temperatures for TiC are lower thanthose for Ti AlC， indicating that the latter hadbetter oxidation resistance than TiC because ofthe intercalation of Al into TiC to form Ti，AlC，. Then， the anomalous oxidation phenomenon in the temperature range 550-650°C was studied. The formation of cracks led to high oxidation kinetics in this temperature range and this accounts for the anomalous oxidation. This suggests that this material should avoid being directly exposed to air in the temperature range 550-650°C. For more details ask for the publication A0453. Instrument ： Setsys Evolution TGA-DSC 16-18 (ambient， 1600-1750°C) www.setaram.com - sales @setaram.com