Effect of CuO on the thermal kinetics and combustion properties of Al/MoO3 thermite prepared by ball milling. Issue 12 (15th June 2021)

• Record Type: Journal Article
• Authors: Chen, Jialin; Guo, Tao; Ding, Wen; Song, Jiaxing; Yao, Miao; Bei, Fengli; Li, Shi
• Is Part Of: Ceramics international. Volume 47:Issue 12(2021)
• Page Start: 16500
• Page End: 16510
• Publication Date: 2021-06-15
• Subjects: Al/MoO3 thermite -- Ball milling -- Thermal kinetics -- Reaction mechanism; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2021.02.218
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: To explore the influence of CuO additive on the thermal kinetics and combustion performance of thermite, Al/MoO3 thermite composites with different mass fractions of CuO were prepared by ball milling. Field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), and differential scanning calorimeter (DSC) were used to test the samples. From the DSC results, Al/MoO3 thermite and Al/CuO thermite released 1066 J/g and 849 J/g heat, respectively. The peak temperature of the exothermic reaction was 560.22 °C and 609.43 °C. Interestingly, the Al/MoO3 thermite with 5% CuO released higher heat, about 1747 J/g. The temperature of the exothermic peak was also greatly advanced to 526 °C. Thermodynamic analysis results showed that the activation energy (Ea) of Al/MoO3 /5% CuO thermite was merely 184.75 kJ mol −1, which was a decrease of 18.3% and 20.8% of the Al/MoO3 and Al/CuO thermite. The reaction mechanism function of Al/MoO3 thermite, Al/MoO3 /5% CuO and Al/CuO thermite can be set as f ( α ) = 1 − α . The fast electric heating wire ignition experiment showed that the flame brightness of the Al/MoO3 /5% CuO thermite was the brightest and the burning time was the longest. Surprisingly, when the mass fraction of CuO additives in Al/MoO3 thermite reached 10% and 20%, the thermal kinetics and combustion performance of the thermite were completely changed. There was a violent and sharp exothermic peak accompanied by a large amount of heat release of 2042 J/g and 2252 J/g, respectively. The reaction mechanism of Al/MoO3 thermite with 10% and 20% CuO addition can be set as f ( α ) = 3 / 2 ∗ ( 1 − α ) [ − ln ( 1 − α ) ] 1 / 3 . The burning speed became faster and the flame was bright with sparks. This work lays the foundation for the further study of the thermite mechanism.