The Effect of Cooling Rate from Solution Treatment Temperature on Phase Constitution and Tensile Properties of Ti-4.3Fe-7.1Cr-3.0Al Alloy
The Effect of Cooling Rate from Solution Treatment Temperature on Phase Constitution and Tensile Properties of Ti-4.3Fe-7.1Cr-3.0Al Alloy
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固溶处理温度冷却速率对Ti-4.3Fe-7.1Cr-3.0Al合金相组成和拉伸性能的影响
DOI：
10.2320/matertrans.45.1566
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发表时间：
2004
影响因子：
1.2
通讯作者：
A. Suzuki
中科院分区：
文献类型：
--
作者：
M. Ikeda;S. Komatsu;M. Ueda;A. Suzuki
钛及钛合金具有比强度高、生物相容性好等优点，是一种极具吸引力的医疗保健和福利用品金属材料。为克服钛合金成本高的障碍，研制了Ti-4.3Fe-7.1Cr-3.0Al合金。该合金具有良好的拉伸性能，即在固溶处理状态下，拉伸强度约为1GPa，伸长率约为20%，断面收缩率约为50%。由于Fe和Cr在β相中的扩散系数高于其他β稳定剂如V和Mo，因此研究固溶处理温度后的冷却速度对拉伸性能的影响是非常重要的。当β相中含有扩散系数较大的β稳定剂时，等温ω析出使合金脆性迅速变大。为了抑制等温ω析出，有必要将冷却速率设定为高于适当值。通过电阻率、维氏硬度和拉伸试验，研究了固溶处理后冷却速度对Ti-4.3Fe-7.1Cr-3.0Al合金相组成和拉伸性能的影响。在以0.46 Ks - 1或更大的冷却速率冷却的Ti-4.3Fe-7.1Cr-3.0Al合金中，通过X射线衍射仅识别出β相，而在通过炉冷却（即，0.024 Ks- 1）冷却的合金中识别出β相和α相。电阻率比在0.46 Ks - 1和34.7 Ks - 1之间几乎保持恒定。在0.024 Ks - 1冷却的样品中，由于相沉淀，电阻率比显著降低，HV急剧增加。拉伸强度在0.46 Ks - 1和34.7 Ks - 1之间保持约1020 MPa。0.024 Ks - 1冷却后，拉伸强度略有提高。伸长率在0.85 Ks - 1和34.7 Ks - 1之间几乎保持不变，然后随着冷却速率的降低而降低，低于0.46 Ks - 1。
Titanium and its alloys are one of very attractive metallic materials for health-care and welfare goods, because these alloys have high specific strength and high biocompatibility However, high cost of Ti alloys is disadvantage in application to the health-care and welfare goods. To overcome high cost barrier of Ti alloys, Ti-4.3Fe-7.1Cr-3.0Al alloy was developed. This alloy has good tensile properties, i.e. about 1 GPa as tensile strength, about 20% as elongation and about 50% as reduction in area, in solution treated state. It is very important that effect of cooling rate from solution treatment temperature on tensile properties is investigated, because diffusion coefficients of Fe and Cr in beta phase are higher than other beta stabilizers, e.g. V and Mo. When a β stabilizer with higher diffusion coefficient is contained in β phase isothermal ω precipitation that makes the alloy brittle becomes fast. To suppress isothermal ω precipitation, it is necessary to set the cooling rate higher than an appropriate value. In this study the effect of cooling rate from solution treatment temperature on phase constitution and tensile properties was investigated by electrical resistivity and Vickers hardness measurement and tensile test in Ti-4.3Fe-7.1Cr-3.0Al alloy. In Ti-4.3Fe-7.1Cr-3.0Al alloy cooled by a cooling rate of 0.46 Ks - 1 or more, only β phase was identified by X-ray diffraction, while β and a phases were identified in the alloy cooled by furnace cooling, i.e. 0.024 Κs - 1 . Resistivity ratio remained almost constant between 0.46 Ks - 1 and 34.7 Ks - 1 . In specimen cooled by 0.024 Ks - 1 , resistivity ratio significantly decreased and HV drastically increased because of a phase precipitation. Tensile strength remained about 1020MPa between 0.46 Ks - 1 and 34.7 Ks - 1 . In specimen cooled by 0.024 Ks - 1 , tensile strength slightly increased. Elongation remained almost constant between 0.85 Ks - 1 and 34.7 Ks - 1 , and then decreased with decrease in cooling rate below 0.46 Ks - 1 .