Fe、Si对工业纯铝晶粒细化的影响

通过AlTiB晶粒细化剂对高纯铝、工业纯铝的细化及Al-10Ti中间合金、Fe、Si对工业纯铝的细化，研究了Fe、Si在工业纯铝晶粒细化过程中的作用。试验结果表明，0.3％的AlTiB晶粒细化剂对工业纯铝有良好的细化效果，但不能细化高纯铝；Fe、Si作为晶粒细化剂单独加入时，有不同程度的细化作用。分析认为，Fe、Si在工业纯铝晶粒细化过程中有双重作用，即促进型壁晶核的游离和增加α-Al在型壁形核的质点数目。     

X70管线钢在近中性及高pH值溶液中的电化学行为和SCC敏感性

采用动电位极化曲线测试法研究了温度、通气条件和pH值对X70管线钢在NS4溶液和0.5 mol/LNa2CO3 1 mol/L NaHCO3溶液中的电化学极化行为的影响,并用慢应变速率试验(SSRT)研究了X70管线钢在这些溶液中的应力腐蚀破裂(SCC)敏感性。结果表明,X70管线钢在NS4溶液中不出现活化—钝化转变区,随外加电位负移,SCC敏感性增加,表现出氢致破裂(HIC)的特征;在0.5 mol/L Na2CO3 1 mol/L NaHCO3高pH值溶液中出现活化—钝化转变区,在阴极极化区,也表现出氢致破裂(HIC)的特征,但在阳极极化区,发生的是阳极溶解型应力腐蚀破裂(ADSCC)。     

镁合金超塑性研究

镁合金在室温下的塑性比较差，但在高温时塑性会有很大程度的改善。AZ31、AZ61、AZ91等合金在较高的温度和较慢的拉伸速率下具有超塑性。最新研究表明镁合金能够在低温和高变形速率下实现超塑性，因而具有工业化应用的可能。综述了镁合金超塑性研究领域的主要成果，分析了该领域研究中尚存在的一些问题，就今后的研究课题及发展方向进行展望。     

Effect of La on the Mechanical Property and Corrosion Resistance of AZ91D

镁合金AZ91D中加入质量分数为1%的La时, 合金在常温下的抗拉强度和延伸率分别增大了21%和101.2%, 并且腐蚀速率下降为原AZ91D的47.2%。其中力学性能的提高主要是由于加入La后形成了(Al, Mg)11La3强化相，同时, 细化了相。耐蚀性的提高则是由于La的加入形成了具有类网状结构的相, 这种类网状结构的相能有效地抑制腐蚀过程的进行, 从而提高了镁合金的耐蚀性。当La加入量进一步增大时, 合金力学性能缓慢增大，但其耐蚀性却明显降低, 特别是当La达到2%时，合金的腐蚀速率甚至高于原合金的腐蚀速率。这主要是由于过多的La导致镁合金基体相的Al含量大大降低, 从而降低了镁合金的耐蚀性。     

基于多CPU数字埋弧自动焊系统数据通信的实现

针对自行开发的基于多CPU数字化埋弧自动焊系统进行了多机通信系统的设计，具体讨论了多机通信的实现。结果表明所设计的通信系统硬件简单，程序易于实现，数据传输距离远，有良好的抗干扰性，并且很好地解决了多机通信的数据冲突问题。     

MESHFREE METHOD BASED ON POINT COLLOCATION FOR METAL FORMING SIMULATION

A meshfree method based on reproducing kernel approximation and point collocation is presented for analysis of metal ring compression. The point collocation method is a true meshfree method without the employment of a background mesh. It is shown that, in a point collocation approach, the remesh problem because of the mesh distortion in FEM （finite element method） and the low efficiency in Galerkin-based meshfree method are avoided. The corrected kernel functions are introduced to the stabilization of free-surface boundary conditions. The solution of symmetric ring compression problem is compared with a conventional finite element solution, and reasonable results have been obtained.     

Luminescent properties of Sr2MgSi2O7 and Ca2MgSi2O7 long lasting phosphors activated by Eu, Dy

Long lasting afterglow phosphors Sr₂MgSi₂O₇:Eu,Dy and Ca₂MgSi₂O₇:Eu,Dy were prepared by solid-state reaction method. It is revealed by the results that both phosphors show two emission peaks that are caused by the different emitting centers Eu²⁺ held in the host lattice. Wavelength shift was observed due to the slight differences in the structure parameters of the two hosts. Investigation on afterglow property shows that Sr₂MgSi₂O₇:Eu,Dy phosphor held a better afterglow property than Ca₂MgSi₂O₇:Eu,Dy phosphor. Thermal simulated luminescence study indicates that the long afterglow is generated by a higher trap concentration formed by the co-doped rare earth ions within the host.     

基于Internet的弧焊机器人远程运动仿真与控制

首先采用MATIAB建立了弧焊机器人工作空间场景模型，基于Internet实现了机器人的远程运动仿真。在仿真的基础上，采用CORBA-CGI方式实现了弧焊机器人的Internet远程控制。仿真和控制试验结果表明，设计的机器人远程运动控制方案是可行的，它有效地克服了网络时延的问题。为基于Internet的机器人远程运动控制奠定了基础。     

管板单边电阻点焊环状焊点力学性能分析

电阻点焊接头的焊接强度由母材和熔核的材料属性及几何特征决定.管板单边电阻点焊由于其焊接结构的特殊性,生成熔核的外形为环状,其强度不能用传统的圆形焊点强度经验公式计算.环状熔核的特征影响因素复杂,物理试验存在不确定性,通过大量试验方法难以建立焊接强度和影响因素之间的关系.基于拉剪试验原理,采用计算机模拟试验和试验设计方法,设计试验并统计得出低碳钢焊接强度和环状熔核几何特征因素之间的关系,并对其影响规律做了深入研究,为环状熔核质量的评估提供了依据.     

Research on the mechanisms of laser forming for the metal plate

Laser forming is a complex thermal–mechanical process. To reveal the mechanisms dominating the forming process is essential to control accurately the deformation of metal plate. Numerous efforts had been made to understand the mechanisms of laser forming. Proposed mechanisms mainly included temperature gradient mechanism, buckling mechanism and upsetting mechanism. However, in the investigation of laser forming, it is found that the above three mechanisms cannot depict fully the process of deformation. Based on the study of thermal transfer and elastic–plastic deformation, the above three mechanisms are further explained. In addition, a new mechanism, coupling mechanism, is proposed. To verify the validity of the mechanisms proposed, numerical simulations are carried out, and simulation results are consistent with analyses of mechanisms. Further analyses of forming mechanisms provide a theoretical basis for the scanning path and heating conditions as well as high-precision forming.