Ni-Al金属间化合物合成机理的研究

Study on the Synthesis Mechanism of Ni-Al Intermetallic Compound

采用粉末冶金法以铝粉和镍粉为原料合成NiAl和Ni3Al金属间化合物粉体,对Ni-Al金属间化合物及相关反应进行了热力学计算,并对不同的反应阶段进行了动力学分析,总结出Ni-Al金属固相反应过程的机理。实验结果表明,Ni-Al金属固相反应生成物形成的顺序为NiAl3→Ni2Al3→NiAl→Ni3Al。Ni粉和Al粉原子配比为1︰1的物料,在750℃左右反应可以获得结晶完整纯度较高的NiAl粉体,反应温度超过铝熔点温度时,升高温度对反应产物的成分影响不大;Ni粉和Al粉原子配比为3︰1的物料,在1 200℃左右反应可以获得结晶完整纯度较高的Ni3Al粉体,提高反应温度有利于提高Ni3Al的转化率。

NiAl and Ni3Al intermetallic compound powders were synthesized from aluminum and nickel powder by powder metallurgy method.The mechanism of Ni-Al metal solid-phase reaction was studied on the thermodynamics data of Ni-Al intermetallic compounds and the dynamics information of the reaction.The results show that the forming order of Ni-Al metal solid-phase interface reaction is： NiAl3→Ni2Al3→NiAl→Ni3Al.At about 750 ℃,high purity and fully crystallized NiAl powder is synthesized from Ni and Al powder mixture with the atomic ratio of 1︰1.The increasing of temperature has little effect on the product ingredient when the temperature is higher than the melting point of aluminum.High purity and fully crystallized Ni3Al powder is obtained from Ni and Al powder mixture with the atomic ratio of 3︰1 at about 1 200 ℃,and the increasing of temperature is beneficial to improve the conversion rate of Ni3Al.