【摘要】 Fe3Al合金是优秀的耐热工程材料,在测定合金流动性工艺参数的基础上,用热力学观点分析了主要添加元素Al对合金流动性的影响规律。根据合金凝固动态曲线的测定结果,Al含量的增加,使凝固区域增宽,由于发达的枝晶阻碍了合金的流动,使流动性下降。合金的液相线温度随Al量的增加而降低,Al含量从24%增至35%时,其过热度约增加1倍。过热度的提高,将有利于合金的流动性提高。研究认为:Al对合金过热带来的有利作用远不及合金结晶温度范围增宽以及高熔点Al2O3数量增多而造成的不利影响。因此,Al含量的增加将导致合金的流动性降低。测试结果表明:Cr元素由于提高合金的液相线温度,使合金的流动性下降。Mo和Zr元素有利于合金流动性的提高。更多还原

【Abstract】 Fe₃Al alloy is an excellent heat resistance engineering material.Based on measuring the flowing technological parameters of Fe₃Al alloy,the effect of the main Al addition on the fluidity of the alloy was analyzed by means of thermodynamic method.The measured dynamitic solidification curve shows that the mushy zone become wider with the increase of Al amount and fluidity decreases as the well developed dendrites hinder the flow of the liquid alloy.The temperature of liquidus decreases with the increase of Al amount.As the Al increases from 24wt% to 35wt%,the superheat degree doubles,which benefits the increase of fluidity of the alloy.The study shows that the favorable effects of the superheat of the alloy due to Al addition are far less prominent than the detrimental ones of wide mushy zone and increased the amount of Al₂O₃ with high melting temperature.Therefore,the increase of Al content will result in the drop of fluidity of the alloy.The measured data indicate that Cr decreases the fluidity of the alloy duo to the increase the liquidus temperature,whereas,Mo and Zr are beneficial to the increase of fluidity.更多还原