Effects of argon plasma and aging on the mechanical properties and phase transformation of 3Y-TZP zirconia

Abstract To evaluate the flexural strength (FS) and flexural modulus (FM) of a commercial 3Y-TZ0P ceramic after artificial aging and either without or with two application times of non-thermal plasma treatments (NTP). In addition, changes in crystalline phase transformation and surface nano-topography after NTP application, during different aging periods, were evaluated. Ninety 3Y-TZP bars (45x4x3 mm) were made for FS and FM testing, and assigned to nine groups (n=10): no NTP/no aging (Control); no NTP/4h aging; no NTP/30h aging; 10s NTP/no aging; 10s NTP/4h aging; 10s NTP/30h aging; 60s NTP/no aging; 60s NTP/4h aging and 60s NTP/30h aging. Artificial accelerated aging was simulated using an autoclave (134º C at 2 bar) for up to 30h. FS and FM were assessed using a universal testing machine and data analyzed using a ANOVA and Tukey test (α=0.05). The volume change in zirconia monoclinic phase (MPV) was evaluated using X-ray diffraction and surface nano-topography was assessed using atomic force microscopy (baseline until 30h-aging). NTP application did not influence the FS and FM of zirconia. Compared to the Control (no NTP/no aging), the FS of zirconia samples treated for 30 hours in autoclave (“no NTP/30h aging” group) increased. Artificial aging for 30 hours significantly increased the FM of zirconia, regardless of NTP application. MPV tended to increase following the increase in aging time, which might result in the surface irregularities observed at 30h-aging. NTP did not alter the zirconia properties tested, but 30h-aging can change the zirconia FS, FM and MPV.

摘要：本研究旨在评估商用3Y-TZ0P陶瓷在人工老化条件下，以及未施加或施加两种时长非热等离子体处理（non-thermal plasma treatments, NTP）后的抗弯强度（flexural strength, FS）与抗弯模量（flexural modulus, FM）。此外，本研究还评估了在不同老化周期内施加NTP后，该陶瓷的晶相转变与表面纳米形貌变化。

本研究制备了90根3Y-TZP试棒（规格为45×4×3 mm）用于抗弯强度与抗弯模量测试，并将其分为9组（每组n=10）：无NTP处理/无老化（对照组）、无NTP处理/老化4 h、无NTP处理/老化30 h、10 s NTP处理/无老化、10 s NTP处理/老化4 h、10 s NTP处理/老化30 h、60 s NTP处理/无老化、60 s NTP处理/老化4 h以及60 s NTP处理/老化30 h。

本研究采用高压灭菌锅（134 ℃、2 bar）模拟人工加速老化，老化时长最长可达30 h。采用万能试验机测试试样的抗弯强度与抗弯模量，检测数据通过单因素方差分析（analysis of variance, ANOVA）与Tukey检验进行统计学分析，检验水准设定为α=0.05。

采用X射线衍射法（X-ray diffraction）评估氧化锆单斜晶相体积分数（monoclinic phase volume, MPV）的变化，采用原子力显微镜（atomic force microscopy）评估试样的表面纳米形貌，检测覆盖基线至老化30 h阶段。

研究结果表明，非热等离子体处理并未对氧化锆的抗弯强度与抗弯模量产生显著影响。与对照组（无NTP处理/无老化）相比，经高压灭菌锅老化30 h的试样（“无NTP处理/30 h老化”组）的抗弯强度有所提升。无论是否施加非热等离子体处理，人工老化30 h均会显著提升氧化锆的抗弯模量。单斜晶相体积分数随老化时长增加呈上升趋势，这可能是导致老化30 h后试样表面出现不规则形貌的原因。非热等离子体处理并未改变本研究测试的氧化锆性能，但30 h人工老化可显著改变氧化锆的抗弯强度、抗弯模量以及单斜晶相体积分数。