By using double glow plasma surface metallurgy technique, the molybdenum （Mo） surface- modified layer on titanium （Ti） was obtained. The corresponding cross-section morphology, phase formation, and element concent...By using double glow plasma surface metallurgy technique, the molybdenum （Mo） surface- modified layer on titanium （Ti） was obtained. The corresponding cross-section morphology, phase formation, and element concentration were investigated by optical microscopy, X-ray diffraction （XRD）, and glow discharge optical emission spectroscopy （GDOES）, respectively. The experimental results indicate that the Mo modified layer is composed of a 1.7 μm pure Mo deposition layer and a 14.3μm Mo diffusion layer. Along the sample thickness direction, nanoindentation tests were performed on the cross-section of the Mo diffusion layer and the Ti substrate （for the comparison purpose） by Hysitron TI900 TriboIndenter. The 2D and 3D residual indentation profiles of the Mo diffusion layer were obtained by scanning probe microscopy （SPM）. The elastic modulus and hardness values of every indent were acquired and analyzed. According to the load-displacement curves, the plastic deformation degrees of the Mo diffusion layer and the Ti substrate were analyzed. It is indicated that the Mo diffusion layer possesses high strength-toughness.展开更多
In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show th...In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show that the sample is brittle when direct aging(A)is applied at 350℃for 1 h after solution treatment(ST).If pre-deformation(D)is performed on the ST sample to induce{332}twins and secondaryα″phase,subsequent aging at 350℃(STDA350)improves the strength to 931 MPa with a good ductility of about 20%maintained.However,when aging is performed at 400℃or 450℃(STDA400/450),the strength can be further improved,but the ductility is dramatically reduced.Atomic-scale characterizations show that the partial collapse ofωphase in the STDA350 sample effectively eliminates aging-induced embrittlement,but complete collapse leads to poor ductility in the STDA400/450 sample.展开更多
In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable struc...In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable structure with expanded crystal lattice distance which improves Li ion diffusion kinetics.The dopants have suppressed the growth of primary particles,formed a coating on the surface,and promoted the elongated morphology.Moreover,the mechanical strength of these particles has increased,as confirmed by the nanoindentation test,which can help suppress particle cracking.The detrimental H2-H3 phase transition has been postponed by 90 mV allowing the cathode to operate at a higher voltage.A better cycling stability over 100 cycles with 69%capacity retention has been observed.We believe this work points out a way to improve the cycling performance,Coulombic efficiency and capacity retention in Ni-rich cathodes.展开更多
对应口腔环境中 p H值发生明显变化以及形成龋齿的自然现象 ,采用加速试验法研究了新型钛合金在不同 p H值乳酸中浸泡的耐腐蚀性能。研究表明当 p H=4即酸性略高于龋齿发病时酸性条件下 ,新型牙科钛合金能够完全耐乳酸腐蚀。在乳酸中腐...对应口腔环境中 p H值发生明显变化以及形成龋齿的自然现象 ,采用加速试验法研究了新型钛合金在不同 p H值乳酸中浸泡的耐腐蚀性能。研究表明当 p H=4即酸性略高于龋齿发病时酸性条件下 ,新型牙科钛合金能够完全耐乳酸腐蚀。在乳酸中腐蚀形式以点蚀为主 ,且随酸性增强有向晶间腐蚀转变的趋势。ICP分析表明合金在乳酸中的溶解析出物主要是 Fe,Fe的加入不利于合金的耐腐蚀性能。热力学计算表明设计的新型钛合金氧化膜含有 Mn2 O3、Nb2 O5、Zr O2 和 Ti O2 中的全部或部分 ,XPS分析表明氧化膜中的确含有 Mn2 O3、Nb2 O5和 Ti O2 ,主要是 Ti O2 。这三种氧化物致密且 Ti O2 和 Nb2 O5耐腐蚀 ,有利于合金的耐腐蚀性能。展开更多
基金Funded by the National Natural Science Foundation of China(No.51171125)the Shanxi Province Science and Technology Key Project(No.20110321051)the Reasearch Project Supported by Shanxi Province Foundation for Returned Overseas Scholars(2011-038)
文摘By using double glow plasma surface metallurgy technique, the molybdenum （Mo） surface- modified layer on titanium （Ti） was obtained. The corresponding cross-section morphology, phase formation, and element concentration were investigated by optical microscopy, X-ray diffraction （XRD）, and glow discharge optical emission spectroscopy （GDOES）, respectively. The experimental results indicate that the Mo modified layer is composed of a 1.7 μm pure Mo deposition layer and a 14.3μm Mo diffusion layer. Along the sample thickness direction, nanoindentation tests were performed on the cross-section of the Mo diffusion layer and the Ti substrate （for the comparison purpose） by Hysitron TI900 TriboIndenter. The 2D and 3D residual indentation profiles of the Mo diffusion layer were obtained by scanning probe microscopy （SPM）. The elastic modulus and hardness values of every indent were acquired and analyzed. According to the load-displacement curves, the plastic deformation degrees of the Mo diffusion layer and the Ti substrate were analyzed. It is indicated that the Mo diffusion layer possesses high strength-toughness.
基金the financial support from the National Natural Science Foundation of China (No. 52374380)the China Postdoctoral Science Foundation (Nos. 2023M730234, 2024T171126)。
文摘In order to overcome the embrittlement of metastable titanium alloys caused by the precipitation ofωiso phase during aging,regulation of isothermalωprecipitation was investigated in Ti−15Mo alloy.The results show that the sample is brittle when direct aging(A)is applied at 350℃for 1 h after solution treatment(ST).If pre-deformation(D)is performed on the ST sample to induce{332}twins and secondaryα″phase,subsequent aging at 350℃(STDA350)improves the strength to 931 MPa with a good ductility of about 20%maintained.However,when aging is performed at 400℃or 450℃(STDA400/450),the strength can be further improved,but the ductility is dramatically reduced.Atomic-scale characterizations show that the partial collapse ofωphase in the STDA350 sample effectively eliminates aging-induced embrittlement,but complete collapse leads to poor ductility in the STDA400/450 sample.
基金support from Queensland University of Technology,Brisbane,Queensland,Australiafinancial support from ARC Discovery Project(DP210103266).
文摘In this work,we have applied molybdenum(Mo)and titanium(Ti)co-doping to solve the degradation of Ni-rich cathodes.The modified cathode,i.e.,Li(Ni_(0.89)Co_(0.05)Mn_(0.05)Mo_(0.005)Ti_(0.005))O_(2) holds a stable structure with expanded crystal lattice distance which improves Li ion diffusion kinetics.The dopants have suppressed the growth of primary particles,formed a coating on the surface,and promoted the elongated morphology.Moreover,the mechanical strength of these particles has increased,as confirmed by the nanoindentation test,which can help suppress particle cracking.The detrimental H2-H3 phase transition has been postponed by 90 mV allowing the cathode to operate at a higher voltage.A better cycling stability over 100 cycles with 69%capacity retention has been observed.We believe this work points out a way to improve the cycling performance,Coulombic efficiency and capacity retention in Ni-rich cathodes.
文摘对应口腔环境中 p H值发生明显变化以及形成龋齿的自然现象 ,采用加速试验法研究了新型钛合金在不同 p H值乳酸中浸泡的耐腐蚀性能。研究表明当 p H=4即酸性略高于龋齿发病时酸性条件下 ,新型牙科钛合金能够完全耐乳酸腐蚀。在乳酸中腐蚀形式以点蚀为主 ,且随酸性增强有向晶间腐蚀转变的趋势。ICP分析表明合金在乳酸中的溶解析出物主要是 Fe,Fe的加入不利于合金的耐腐蚀性能。热力学计算表明设计的新型钛合金氧化膜含有 Mn2 O3、Nb2 O5、Zr O2 和 Ti O2 中的全部或部分 ,XPS分析表明氧化膜中的确含有 Mn2 O3、Nb2 O5和 Ti O2 ,主要是 Ti O2 。这三种氧化物致密且 Ti O2 和 Nb2 O5耐腐蚀 ,有利于合金的耐腐蚀性能。
