利用X射线衍射(XRD)及差热分析(DSC)等方法研究了添加B对Zr Ti Cu Ni Be块状非晶合金的形成、结晶及热稳定性的影响·结果表明:在Zr Ti Cu Ni Be合金系中添加B可明显改变该合金的玻璃转变温度Tg,一次结晶温度Tx及过冷液相区ΔT等参...利用X射线衍射(XRD)及差热分析(DSC)等方法研究了添加B对Zr Ti Cu Ni Be块状非晶合金的形成、结晶及热稳定性的影响·结果表明:在Zr Ti Cu Ni Be合金系中添加B可明显改变该合金的玻璃转变温度Tg,一次结晶温度Tx及过冷液相区ΔT等参数·当y(B)≤3%时,B的添加可使合金保持块状非晶,提高Tg、Tx并扩大过冷液相区,使非晶热稳定性增加;当y(B)≥6%时,B的添加将诱导大量的粗大Zr2Cu及ZrB2等晶体的析出·由于它们非纳米晶,尺寸较大,形状不规整,不能作为非晶复合材料的增强体·展开更多
Martensitic transformation,mechanical and thermomechanical properties of a Ti-rich Ti52Ni23Cu25 melt spun ribbon annealed at a temperature below the crystallization temperature were studied by XRD,DSC and DMA.After an...Martensitic transformation,mechanical and thermomechanical properties of a Ti-rich Ti52Ni23Cu25 melt spun ribbon annealed at a temperature below the crystallization temperature were studied by XRD,DSC and DMA.After annealing the initially amorphous ribbon at 400℃for 10 h,the ribbon is fully crystallized and exhibits one-stage B2-B19 phase transformation with the temperature hysteresis of 14℃.The annealed ribbon is composed of B2,B19 and B11-TiCu phase with(001)preferential orientation. On the stress―strain curves,the rearrangement of the martensite variants and stress-induced martensitic transformation are observed below the Mf temperature and above the Af temperature,respectively.The annealed ribbon exhibits up to 1.6%superelastic shape recovery with small stress hysteresis of 25 MPa.No flat stress-plateau is associated with the superelasticity.The annealed ribbon shows a well-defined shape memory effect during thermal cycling from-60 to 100℃.The transformation strain and recovery strain increase with increasing the applied external stress.Under the external stress above 150 MPa,the shape recovery strain is not sensitive to it and keeps stable at about 1.74%.展开更多
In order to attain high-quality Ti-Ni-Cu film,the surface morphologies,chemical compositions and mechanical properties of Ti-Ni-Cu thin films prepared by direct current(DC)magnetron sputtering at various processes wer...In order to attain high-quality Ti-Ni-Cu film,the surface morphologies,chemical compositions and mechanical properties of Ti-Ni-Cu thin films prepared by direct current(DC)magnetron sputtering at various processes were characterized by scanning electron microscopy(SEM),X-ray diffractometer(XRD)and tensile tests.The type of substrates,Ar pressure and sputtering power had significant effects on the quality and chemical composition of Ti-Ni-Cu thin film.Compared with Si and SiO_(2) slides,it was easier to obtain freestanding films by adopting glass or piezoid slide as substrates.The Ti-Ni-Cu thin film deposited at lower pressure(0.10 Pa)had a better density.The surface was featured with porous structure in the Ti-Ni-Cu thin film prepared by higher Ar pressure of 0.36 Pa.In addition,both the tensile strength and strain of annealed Ti-Ni-Cu thin film continuously increased with Ar pressure decreasing.Higher density contributed to the superior mechanical properties.The deposition rate firstly increased and then decreased with Ar pressure and sputtering power increasing.The composition of deposited Ti-Ni-Cu film can be tailored by changing sputter power.The deposited Ti-Ni-Cu thin films at different processing parameters were in amorphous state.In short,the present study offered the important theoretical basis for the preparation of Ti-Ni-Cu thin film with higher quality and performance.展开更多
文摘利用X射线衍射(XRD)及差热分析(DSC)等方法研究了添加B对Zr Ti Cu Ni Be块状非晶合金的形成、结晶及热稳定性的影响·结果表明:在Zr Ti Cu Ni Be合金系中添加B可明显改变该合金的玻璃转变温度Tg,一次结晶温度Tx及过冷液相区ΔT等参数·当y(B)≤3%时,B的添加可使合金保持块状非晶,提高Tg、Tx并扩大过冷液相区,使非晶热稳定性增加;当y(B)≥6%时,B的添加将诱导大量的粗大Zr2Cu及ZrB2等晶体的析出·由于它们非纳米晶,尺寸较大,形状不规整,不能作为非晶复合材料的增强体·
基金Project(05-2-JC-76)supported by the Technological Generalship Program of Qingdao City,ChinaProject(20050360646)supported by National Foreign Expert Key Foundation of China
文摘Martensitic transformation,mechanical and thermomechanical properties of a Ti-rich Ti52Ni23Cu25 melt spun ribbon annealed at a temperature below the crystallization temperature were studied by XRD,DSC and DMA.After annealing the initially amorphous ribbon at 400℃for 10 h,the ribbon is fully crystallized and exhibits one-stage B2-B19 phase transformation with the temperature hysteresis of 14℃.The annealed ribbon is composed of B2,B19 and B11-TiCu phase with(001)preferential orientation. On the stress―strain curves,the rearrangement of the martensite variants and stress-induced martensitic transformation are observed below the Mf temperature and above the Af temperature,respectively.The annealed ribbon exhibits up to 1.6%superelastic shape recovery with small stress hysteresis of 25 MPa.No flat stress-plateau is associated with the superelasticity.The annealed ribbon shows a well-defined shape memory effect during thermal cycling from-60 to 100℃.The transformation strain and recovery strain increase with increasing the applied external stress.Under the external stress above 150 MPa,the shape recovery strain is not sensitive to it and keeps stable at about 1.74%.
基金financially supported by the National Natural Science Foundation of China(Nos.51801023,51871080 and 51571073)the Industrial Transformation&Upgrading of Strong Base Project of China(No.TC150B5C0/03)。
文摘In order to attain high-quality Ti-Ni-Cu film,the surface morphologies,chemical compositions and mechanical properties of Ti-Ni-Cu thin films prepared by direct current(DC)magnetron sputtering at various processes were characterized by scanning electron microscopy(SEM),X-ray diffractometer(XRD)and tensile tests.The type of substrates,Ar pressure and sputtering power had significant effects on the quality and chemical composition of Ti-Ni-Cu thin film.Compared with Si and SiO_(2) slides,it was easier to obtain freestanding films by adopting glass or piezoid slide as substrates.The Ti-Ni-Cu thin film deposited at lower pressure(0.10 Pa)had a better density.The surface was featured with porous structure in the Ti-Ni-Cu thin film prepared by higher Ar pressure of 0.36 Pa.In addition,both the tensile strength and strain of annealed Ti-Ni-Cu thin film continuously increased with Ar pressure decreasing.Higher density contributed to the superior mechanical properties.The deposition rate firstly increased and then decreased with Ar pressure and sputtering power increasing.The composition of deposited Ti-Ni-Cu film can be tailored by changing sputter power.The deposited Ti-Ni-Cu thin films at different processing parameters were in amorphous state.In short,the present study offered the important theoretical basis for the preparation of Ti-Ni-Cu thin film with higher quality and performance.
