Tabbin Institute for Metallurgical Studies, Cairo, Egypt.
Central Metallurgical R&D Institute, Cairo, Egypt.
Sci Rep. 2023 Jun 1;13(1):8878. doi: 10.1038/s41598-023-35883-1.
This study aims at investigating worn surface topography and mathematical modeling of annealed Ti-6Al-3Mo-2Sn-2Zr-2Nb-1.5Cr alloy using response surface methodology (RSM). The alloy was subjected to three different regimes in order to study their effect on mechanical properties. First regime was applying cold deformation by compression until 15% drop in height at room temperature. The second regime was performing solution treated on the deformed samples at 920 °C for 15 min then air-cooled (AC) to ambient temperature. Third regime was applying aging on the deformed and solution treated specimen for 4 hr at 590 °C followed by air-cooling. Three different velocities (1, 1.5, and 2 m/s) were adopted to conduct dry sliding wear according to the experimental design technique (EDT). Gwyddion and Matlab softwares were used to detect worn surface photographs analytically and graphically. Maximum hardness of 425 HV was obtained for AC+Aging specimen, while minimum hardness of 353 HV was reported for the annealed specimen. Applying aging process after solution treatment enhanced considerably the wear property and this enhancement reached 98% as compared to the annealed condition. The relationship between input factors (hardness & velocity) and responses (Abbott Firestone zones) was demonstrated using analysis of variance (ANOVA). The best models for Abbott Firestone zones (high peaks, exploitation, and voids) produced accurate data that could be estimated for saving time and cost. The results showed that the average surface roughness increases with increasing sliding velocity for all conditions except AC+Aging condition where the average surface roughness decreased with increasing sliding velocity. The results revealed that at low velocity and hardness, the material gives the highest exploitation zone (86%). While at high velocity and hardness, the material gives the lowest exploitation zone (70%). In general, the predicted results of mathematical model showed close agreement with experimental results, creating that models could be utilized to predict Abbott Firestone zones satisfactorily.
本研究旨在通过响应面法（RSM）研究退火 Ti-6Al-3Mo-2Sn-2Zr-2Nb-1.5Cr 合金的磨损表面形貌和数学建模。该合金经历了三种不同的状态，以研究它们对机械性能的影响。第一阶段是在室温下通过压缩将冷变形减少 15%。第二阶段是对变形样品在 920°C 下进行固溶处理 15 分钟，然后空冷（AC）至环境温度。第三阶段是对变形和固溶处理的样品在 590°C 下时效 4 小时，然后空冷。根据实验设计技术（EDT），采用三种不同的速度（1、1.5 和 2 m/s）进行干滑动磨损。使用 Gwyddion 和 Matlab 软件对磨损表面照片进行分析和图形化检测。AC+时效试样的最大硬度为 425HV，而退火试样的最小硬度为 353HV。固溶处理后进行时效处理，大大提高了耐磨性，与退火状态相比，提高了 98%。通过方差分析（ANOVA）展示了输入因素（硬度和速度）与响应（Abbott Firestone 区）之间的关系。Abbott Firestone 区（高峰、开采和空洞）的最佳模型生成了准确的数据，可以节省时间和成本。结果表明，除了 AC+时效条件外，所有条件下的平均表面粗糙度都随滑动速度的增加而增加，在 AC+时效条件下，平均表面粗糙度随滑动速度的增加而降低。结果表明，在低速度和低硬度下，材料的开采区最高（86%）。而在高速度和高硬度下，材料的开采区最低（70%）。总的来说，数学模型的预测结果与实验结果非常吻合，表明模型可以很好地用于预测 Abbott Firestone 区。
