彭志坚
,
杨义勇
,
王成彪
,
付志强
金属学报
设计、制备了三个系列(不同Bi2O3与Sb2O3掺杂浓度)的ZnO基复合材料. 力学性能测试的结果表明, Bi含量(2%, 原子分数)保持不变, 随Sb含量(在合适的剂量范围内)的增大,由于基质ZnO晶粒减小, 陶瓷致密度增大, 所得材料的模量、抗弯强度以及断裂韧性均增大; Sb含量(3%, 原子分数)保持不变, 随Bi含量的增大, 由于基质ZnO晶粒增大、陶瓷致密度减小, 所得材料的模量、抗弯强度以及断裂韧性均减小.在设计组成范围内材料的最佳力学性能约为: 弹性模量114 GPa, 弯曲模量115 GPa, 抗弯强度120 MPa, 断裂韧性1.87 MPa×1/2.
关键词:
ZnO
,
Dopants
,
Composite ceramic varistors
,
Mechanical properties
,
null
Wang Chang
,
Yu Zhentao
,
Cui Yajun
,
Zhang Yafeng
,
Yu Sen
,
Qu Gongqi
,
Gong Haibo
材料科学技术（英）
doi:10.1016/j.jmst.2016.08.008
In recent years, zinc based alloys as a new biodegradable metal material aroused intensive interests. However, the processing of Zn alloys micro-tubes (named slender-diameter and thin-walled tubes) is very difficult due to their HCP crystal structure and unfavorable mechanical properties. This study aimed to develop a novel technique to produce micro-tube of Zn alloy with good performance for biodegradable vascular stent application. In the present work, a processing method that combined drilling, cold rolling and optimized drawing was proposed to produce the novel Zn-5Mg-1Fe (wt%) alloy micro-tubes. The micro-tube with outer diameter of 2.5?mm and thickness of 130?μm was fabricated by this method and its dimension errors are within 10?μm. The micro-tube exhibits a fine and homogeneous microstructure, and the ultimate tensile strength and ductility are more than 220?MPa and 20% respectively. In addition, the micro-tube and stents of Zn alloy exhibit superior in vitro corrosion and expansion performance. It could be concluded that the novel Zn alloy micro-tube fabricated by above method might be a promising candidate material for biodegradable stent.
关键词:
Zn alloy
,
Micro-tube
,
Biodegradable stent
,
Mechanical properties
,
Dimensional accuracy
,
In vitro corrosion performance
Mi Jin Koh Hae Young Hwang Deuk Ju Kim Hyeng Jun Kim Young Taik Hong
材料科学技术（英）
Polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) / clay nanocomposite membranes were prepared by phase inversion method through controlling retention time to apply for a lithium ion secondary batteries. Increased membrane porosity with macrovoids was observed at increasing retention time. Partially intercalated structures of PVdF-HFP/clay nanocomposite membranes were confirmed by X-ray diffraction (XRD) analysis. PVdF-HFP membranes containing various kind of clay showed the increase of membrane modulus compared to the pristine PVdF-HFP membrane.
关键词:
PVdF-HFP
,
Porosity
,
Mechanical properties
,
Clay
,
Separator
Wang C.
,
Yang H.T.
,
Li X.
,
Zheng Y.F.
材料科学技术（英）
doi:10.1016/j.jmst.2016.06.003
In this work, three widely used commercial Zn alloys (ZA4-1, ZA4-3, ZA6-1) were purchased and prepared by hot extrusion at 200?°C. The microstructure, mechanical properties, corrosion behaviors, biocompatibility and hemocompatibility of Zn alloys were studied with pure Zn as control. Commercial Zn alloys demonstrated increased strength and superb elongation compared with pure Zn. Accelerated corrosion rates and uniform corrosion morphologies were observed in terms of commercial Zn alloys due to galvanic effects between Zn matrix and α-Al phases. 100% extracts of ZA4-1 and ZA6-1 alloys showed mild cytotoxicity while 50% extracts of all samples displayed good biocompatibility. Retardant cell cycle and inhibited stress fibers expression were observed induced by high concentration of Zn2+ releasing during corrosion. The hemolysis ratios of Zn alloys were lower than 1% while the adhered platelets showed slightly activated morphologies. In general, commercial Zn alloys possess promising mechanical properties, appropriate corrosion rates, significantly improved biocompatibility and good hemocompatibility in comparison to pure Zn. It is feasible to develop biodegradable metals based on commercial Zn alloys.
关键词:
Commercial Zn alloys
,
Biodegradable metals
,
Mechanical properties
,
Corrosion behaviors
,
Cytotoxicity
,
Hemocompatibility
李杰华
,
介万奇
,
杨光昱
金属学报
本文通过光学显微镜、X射线衍射仪、扫描电镜等分析研究了合金化元素Zn对GW系镁合金砂型铸造组织和性能的影响。研究结果表明：GW系镁合金的结构类型和Mg（六方相）相同，Gd溶入Mg的晶格形成置换固溶体，组织中存在着Mg24Y5第二相。加入合金化元素Zn后，组织发生较大变化，形成雪花状的枝晶，而且在固溶以及时效处理过程中，其形貌没有消失，只是有所溶解。实验合金GWZ721在砂型铸造工艺条件下热处理后的室温力学性能优良，抗拉强度达到250MPa，屈服强度甚至达到235MPa，远远优于商品镁合金AZ91C（85 MPa）与ZK51 A（140 MPa），而且塑性也比较好，最高达到6.2%。砂型铸造试验合金GWZ721热处理后的高温瞬时拉伸性能也相当优良，在200℃、250℃和300℃时，实验合金的抗拉强度分别达到225MPa、220MPa和205MPa。抗拉强度和屈服强度随着温度的升高均有所下降，但下降不多，延伸率则随着温度的升高有所上升。通过向GW系铸造镁合金添加合金化元素Zn，改善了实验合金GW72的组织，实验合金GW721在保证提高力学性能的前提下降低了成本，是一种较有前途的高端镁合金材料。
关键词:
显微组织
,
Mechanical properties
,
GW series cast magnesium alloys
Zhimin ZHOU
,
Yong ZHOU
,
Mingjun WANG
,
Chunsheng YANG
,
Ji'an CHEN
,
Wen DING
,
Xiaoyu GAO
,
Taihua ZHANG
材料科学技术（英）
Microbridge testing was used to measure the Young's modulus and residual stress of metallic films. Samples of freestanding NiFe film microbridge were fabricated by microelectromechanical systems. Special ceramic shaft structure was designed to solve the problem of getting the load-deflection curve of NiFe film microbridge by the Nanoindenter XP system with normal Berkovich probe. Theoretical analysis of load-deflection curves of the microbridges was proposed to evaluate the Young's modulus and residual stress of the films simultaneously. The calculated results based on experimental measurements show that the average Young's modulus and residual stress for the electroplated NiFe films are 203.2 GPa and 333.0 MPa, respectively, while the Young's modulus measured by the Nano-hardness method is 209.6±11.8 GPa for the thick NiFe film with silicon substrate.
关键词:
Mechanical properties
,
金属薄膜
,
纳米压痕
Xueshan XIAO
,
Weihuo LI
,
Lei XIA
,
Shoushi FANG
,
Qin HUA
,
Yu
,
a DONG
材料科学技术（英）
Quasistatic and dynamic tensile behavior of Zr52.5Al10Ni10Cu15Be12.5 bulk amorphous alloy was investigated at the strain rates of 10-4~103 s-1 by using a Shimadzu AG-100KNA autograph and a pneumatic tensile impact tester. It was shown that the tensile fracture strength and the fracture morphology were sensitive to the strain rate. With the increase of the strain rate, the tensile fracture strength decreased and the fracture morphology changed from cleavage into quasi-cleavage, and then into a mixture of microvoid-coalescence dimples and quasi-cleavage veins.
关键词:
Mechanical properties
,
null
,
null
Guimei WANG
,
Xigao JIAN
,
Gongxiong LIAO
,
Lihao WU
材料科学技术（英）
Poly (phthalazinone ether sulfone ketone) (PPESK) was melt blended with bisphenol-A polysulfone oligomer (O-PSF) to produce a thermoplastic polymer blends. The miscibility, thermal stability, rheological and mechanical properties of the blends were investigated by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and capillary rheometry. The blends showed single Tg over the composition range and possess homogeneous microstructure. The addition of O-PSF slightly affected the thermal properties of the blends. PSF oligomer, as a processing aid, could markedly improve the processability of the PPESK. In addition, the mechanical properties of the blends were increased, to some degree, by adding O-PSF.
关键词:
PPESK
,
null
,
null
,
null
,
null
,
null
