Ti对热型连铸Cu-Al-Ni合金晶粒长大的阻碍作用

Effects of Ti addition on grain growth of Cu-Al-Ni alloy cast by heated mold continuous casting process

为阻止热型连铸Cu-Al-Ni合金在热加工过程中晶粒长大．导致性能恶化。可在合金中加入Ti细化晶粒．当含Ti质量分数为0．2％～0．4％时可形成细小的X相。能够有效细化晶粒．在900℃加热保温10min．X相很容易在晶界处聚集．阻止晶粒的运动。从而阻止了晶粒的长大．但同时使合金变得很脆．试样的拉伸试验表明．对加Ti的合金．其屈服应力升高．对塑性变形的应变量没有影响．

Ti is added to Cu-Al-Ni alloys cast by heated mold continuous casting process in order to prohibit grain growth during heating, which would cause performance degradation. Tiny X-phase forms in w（Ti）= 0.2%-0.4% addition. The X-phase particles disperse in grain boundary and inside the grains, thus stop the grain boundary movement. The X-phase aggregate in the grain boundaries easily after heating at 900℃ holding 5-20 min, resulting in alloy brittle. Tensile tests show that with Ti addition, yield stress inereases while plastic strain remains no change.