G.V.V.SURYAKIRAN
,
K.HARIKRISHNA
,
Sk.SAMEER
,
M.BHARGAVI
,
B.SANTOSHKUMAR
,
G.MOHANARAO
,
Y.NAIDUBABU
,
RAVIKUMARDUMPALA
,
B.RATNASUNIL
中国有色金属学报(英文版)
doi:10.1016/S1003-6326(17)60092-X
搅拌摩擦加工细化AZ91镁合金,研究钻孔过程中不同切割速度和进料速率下晶粒尺寸和二次相对加工特性的影响.经搅拌摩擦加工得到了过饱和AZ91镁合金,晶粒尺寸由(166.5±8.7)μm细化到(21.7±13.5)μm.相比未加工的AZ91镁合金(HV(108.2±15.6)),经搅拌摩擦加工的合金硬度为HV(88.95±6.1),这归因于二次相的减少.然而,搅拌摩擦加工AZ91合金的平均切割力略微减小.相比未加工的AZ91镁合金,搅拌摩擦加工AZ91合金的钻孔边缘损伤较低.因此,虽然在钻孔过程中晶粒细化可以略微增大切割力,但在AZ91镁合金加工过程中边缘处理较好.
关键词:
镁合金
,
搅拌摩擦加工
,
机械加工
,
晶粒尺寸
,
显微组织
刘勤
,
周善佑
材料研究学报
超塑性m-δ关系曲线可以分为m_L=m_(max)和m_L=m_(min)两大类型。均可由下面的C.L.(刘勤)m-σ方程表示:σ(%)=〔cε~(m-m_0)-1〕×100当σ=σ_0=0时,m=m_0≠0,C=C_0=κ_0/κ_0=1。当σ=σ_1(σ_(11),σ_(12),σ_(13),…,)时,m=m_1(m_(11),m_(12),m_(13),…),C=C_1(C_(11),C_(12),C_(13),…)=κ_1(κ_(11),κ_(12),κ_(13),…)/κ_0,当σ=σ_F时,m=m_F,C=C_F=κ_F/κ_0。对C 值进行“规划”,得到的C_1~(σ_O-σ_L)-(m_L=m_(max)),C_2~(σ_F-σ_L)-(m_L=m_(min)),C_3~(m_0-m_L)-(m_L=m_(max)和C_4~(m_F-m_L)-(m_L=m_(min))四种类型的“规划”方程分别对m_L=m_(max)和m_L=m_(min)型m-σ曲线适用。若m-σ曲线属简单的下降式,C 及其“规划”值均可近似地取1。否则,C-σ关系是应加以研究的问题。m 和k 值对σ值的效应可以分为动态(直接)和静态(间接)两种。最后的σ值是两种效应的综合结果。(注:m 和κ值见基本方程σ=κε~m)
关键词:
齐召庆
,
汪宏涛
,
薛明
功能材料
doi:10.3969/j.issn.1001-9731.2016.02.010
采用改进的非接触式混凝土收缩测定仪及标靶,研究了m(M)/m(P)比值(MgO与KH2PO4的质量比)对磷酸镁水泥石自收缩行为的影响,运用八通道微量量热仪、压汞仪、X射线衍射仪、扫描电子显微镜及能谱仪等分析手段,分析了m(M)/m(P)比值对磷酸镁水泥石自收缩的作用机理.结果表明,磷酸镁水泥石的自收缩呈现出3个阶段的特征,即早期的迅速收缩阶段、微膨胀阶段、收缩缓慢发展阶段.随着m(M)/m(P)比值的增大,由于磷酸镁水泥石的水化放热量降低,水泥石内部孔隙率增大,水化产物结晶度降低,水泥石结构疏松,所以,自收缩率减小.
关键词:
磷酸镁水泥
,
自收缩
,
m(M)/m(P)比值
Tesshu Miyahara
材料科学技术（英文）
Magnetic stripe is one of the major applications of magnetic materials. As a key component of the present card technologies magnetic stripes play reliable components for electronic data interchange in worldwide electronic payment systems such as financial cards, transit tickets and phone cards, etc. Magnetic stripes are available in various coercivity materials, widths, lengths, structures and colors with each types of transferable, lamination and pressure sensitive magnetic tapes of Deuton-M. Manufacturing process, structure and characteristics of Deuton-M magnetic tape and sheet are described.
关键词:
卞进田
,
孙晓泉
,
聂劲松
量子电子学报
doi:10.3969/j.issn.1007-5461.2008.02.019
为了得到2.7 μm波段可调谐激光辐射,设计了信号光单谐振荡KTP光参量振荡器(OPO),给出了KTP OPO II(B)类相位匹配方式下的角度调谐曲线、有效非线性系数.KTP晶体切割角为θ=62°,ψ=0°,有效非线性系数为-2.97 pm/V.利用该KTP OPO实现了2.6～2.8 μm波段范围可调谐激光输出,用脉宽为16 ns的基模高斯光束1.064 μm激光泵浦得到了最大能量578 μJ,能量转换效率达1.7%.
关键词:
非线性光学
,
可调谐红外激光
,
单谐振光参量振荡器
,
KTP
,
角度调谐
,
相位匹配
Journal of Physics-Condensed Matter
We investigated the stable (0001) surfaces of M(2)AlC (M = Ti, V and Cr) using the first-principles plane-wave pseudopotential total energy method. Four possible (0001) terminations were considered by breaking the M-Al and M-C bonds. The corresponding surface energies were calculated and compared. The Al-and M(C)-terminated (0001) surfaces demonstrated better stability than the C- and M(Al)-terminated surfaces by their much lower surface energies. In addition, the stability of surfaces was predicted under various chemical environments as a function of chemical potentials. We further investigated the character of surface relaxations. The electronic structures of the stable Al- and M(C)-terminated surfaces were analyzed.
关键词:
ab-initio calculations;ti3sic2 thin-films;electronic-structure;elastic stiffness;al;deposition;cr2alc;simulation;adhesion;solids
邱闽旺
,
涂朝阳
,
李坚富
,
黄奕川
,
汪爱栋
,
唐鼎元
,
王元康
量子电子学报
doi:10.3969/j.issn.1007-5461.2001.04.012
本文报道了我所生长的掺钕钨酸钾钆(KGW)晶体的脉冲激光特性.当用氙闪光灯泵浦时,尺寸为φ3.4 mm×24 mm的KGW激光棒,最大激光输出为每个脉冲358.4mJ,总效率为1.7%,斜率效率为3.3%,波长为1.067μm.实验证明,KGW是一种很有前途的小型激光器工作物质.
关键词:
掺钕钨酸钾钆(KGW)晶体
,
1.067 μm激光
