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通过镦锻试验和模锻实验研究了Ti-Cu系合金半固态锻造行为,并对锻材进行了拉伸试验,讨论了Cu含量对半固态可锻性及力学性能的影响。结果表明:1000°C至1150°C半固态锻造较常规锻造具有较小的顶锻压力;其中,1000°C至1050°C间半固态锻造的Ti-Cu系合金均表现出较好的可锻性,在75%的锻造变形量下无明显缺陷。分析认为,Ti-Cu系列合金中含有较多的低熔点Ti_2Cu相,随着半固态温度升高或Cu含量的增加,材料中的液相含量增加,增加的液相含量对变形起到润滑作用,减少了固相变形引起的应力集中,有效地降低了变形抗力,改善了成形性。力学性能研究表明:半固态锻造Ti-Cu系合金较常规锻造合金强度升高,塑性降低。随着Cu含量的升高,合金的强度明显提升,塑性降低。分析认为:力学性能的变化主要是由于Ti_2Cu相析出含量、形态和分布相关,随着Cu含量和半固态温度的升高,更多Ti_2Cu相在晶内和晶界析出,引起析出强化作用,同时,晶界析出的针状Ti_2Cu相形成了偏析带,降低了合金塑形。
The semi-solid forging behavior of Ti-Cu alloy was studied by upsetting and die-forging experiments. The tensile test was carried out on the as-cast Ti-Cu alloys. The effect of Cu content on semi-solid malleability and mechanical properties was also discussed. The results show that the semi-solid forging at 1000 ° C to 1150 ° C has a smaller upsetting pressure than conventional forging; among them, the semi-solid forged Ti-Cu alloys at 1000 ° C to 1050 ° C all show good Forge, no significant defects at 75% forging deformation. The analysis shows that the Ti-Cu alloy contains more low-melting Ti 2 Cu phases. As the semi-solid temperature increases or the Cu content increases, the liquid phase content increases and the increased liquid content lubricates the deformation , Reducing the stress concentration caused by the solid phase deformation, effectively reducing the deformation resistance and improving the formability. Mechanical properties of the study showed that: semi-solid forged Ti-Cu alloy forging strength than conventional forging, plasticity decreased. With the increase of Cu content, the strength of the alloy increased obviously and the plasticity decreased. The analysis shows that the change of mechanical properties is mainly due to the precipitation content of Ti 2 Cu phase, which is related to the morphology and distribution. With the increase of Cu content and semi-solid temperature, more Ti 2 Cu phase precipitates in the grain boundary and grain boundary, , The precipitated acicular Ti_2Cu phase formed grain boundary segregation zone, reducing the alloy shape.