The mechanism of thermal explosion (TE) synthesis of TiC–TiB2 particulate locally reinforced steel matrix composites from an Al–Ti–B4C system via a TE-casting route
The mechanism of thermal explosion (TE) synthesis of TiC–TiB2 particulate locally reinforced steel matrix composites from an Al–Ti–B4C system via a TE-casting route
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DOI：
10.1016/j.matchemphys.2011.10.051
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发表时间：
2012-01
影响因子：
4.6
通讯作者：
B. Zou;P. Shen;Xueqiang Cao;Q. Jiang
中科院分区：
文献类型：
--
作者：
B. Zou;P. Shen;Xueqiang Cao;Q. Jiang
采用一种新的TE铸造工艺，从不同B4 C颗粒尺寸的Al-Ti-B4 C体系制备了TiC-TiB 2颗粒局部增强钢基复合材料。研究了局部增强区TiC和TiB 2的形成机制。结果表明，当Al-Ti-B-C熔体中B和C原子浓度达到饱和时，B4 C分解进入Al-Ti熔体，形成TiC和TiB 2析出。然而，在使用粗B_4C粉末（≥40μm）的情况下，由于B_4C的分解不良，在Al-Ti-B-C熔体中的初级反应相当有限。由于Fe液与残余B_4 C发生了良好的反应，浇注的钢液渗入到反应产物中，形成了Al-Fe-Ti-B-C熔体，并进一步析出TiC和TiB_2。提出了在电阻炉中热爆合成TiC和TiB 2的机理与在铸造过程中热爆合成TiC和TiB 2的机理之间的关系。
TiC–TiB2particulate locally reinforced steel matrix composites were fabricated by a novel TE-casting route from an Al–Ti–B4C system with various B4C particle sizes. The formation mechanism of TiC and TiB2in the locally reinforced regions was investigated. The results showed that TiC and TiB2are formed and precipitated from Al–Ti–B–C melt resulting from the dissociation of B4C into Al–Ti melt when the concentrations of B and C atoms in the Al–Ti–B–C melt become saturated. However, in the case of coarse B4C powders (≥40μm) used, the primary reaction in the Al–Ti–B–C melt is quite limited due to the poor dissociation of B4C. The poured steel melt infiltrates into the primary reaction product and thus leads to the formation of Al–Fe–Ti–B–C melt, thanks to the favorable reaction of molten Fe with remnant B4C, and then TiC and TiB2are further formed and precipitated from the saturated Al–Fe–Ti–B–C melt. The relationship between the mechanisms of thermal explosion (TE) synthesis of TiC and TiB2in the electric resistance furnace and during casting was proposed.