经不同熔体处理的罐用铝材的高温拉伸性能试验

通过高温拉伸试验,并结合OM、DTA、SEM、EDAX和TEM等分析手段,探讨了经不同熔体处理的压力罐用铝材（简称“铝原块”）的高温拉伸性能和微观组织的变化规律.结果表明,冶金缺陷的存在是铝原块高温塑性难以充分发挥的主要限制因素,并直接影响到铝材断裂破坏的微观过程,是主要的裂纹源;与未处理和常规处理比较,高效熔体处理技术有效地改善和提高了铝原块的冶金质量,使得材料的高温变形较均匀,其高温断裂方式为穿晶微孔聚集型,断口韧窝较深且分布较均匀,显著提高了其高温塑性;经高效熔体处理的铝原块的变形温度应低于500 ℃,否则会由于晶粒粗大并易产生低熔点共晶物富Fe（Si）杂质相的溶解而显著降低材料的高温塑性变形性能,其合适的变形温度为400～450 ℃;采用较低品位工业纯铝经高效熔体处理而获得的铝原块,其主要塑性变形性能不低于现产品性能,其用料低品化是可行的.     

电子封装SiCp/Al复合材料的制备与性能

研究了无压渗透法制备电子封装SiCp/Al复合材料过程中,烧结工艺对SiC预制件开孔率、抗压强度的影响,以及渗透工艺对Al液渗透形成复合材料的影响,并对所制备的复合材料热物理性能和表面涂覆进行了评价。结果表明,经1100℃分段烧结的SiC预制件开孔率、抗压强度较好;Al液浇铸温度、保温温度分别在750～850℃、800～900℃的范围时,SiC预制件的渗透效果较好;所制备的55%SiCp/Al复合材料相对密度为98.3%,热膨胀系数在（7.23～9.97）×10-6K^-1之间变化,热导率为146.5～172.3W/（m.K）,复合材料表面涂覆性能可行性好。     

富Y重稀土对ZM5合金组织和性能影响的研究

以ZM5镁合金为基体材料，以富Y重稀土为添加原料，应用铸造方法制备了稀土镁合金。利用光学金相显微镜（OM）、X衍射分析、拉伸试验和腐蚀试验等方法，考察分析了稀土Y对ZM5合金铸造组织结构、力学性能和腐蚀性能的影响。结果表明，铸态合金中出现了新相Al3La、MgY，它对于减少晶界处第2相的析出、晶粒的细化以及力学性能的提高起着积极作用。同时，稀土的加入明显地改善了合金的腐蚀性能。     

电渣熔铸模具钢/低合金钢双金属平板件的制备与性能

采用电渣熔铸方法制备了Cr12MoV/40Cr双金属平板件,研究了熔铸及热处理工艺对双金属组织和性能的影响.结果表明:使电极与结晶器产生相对运动或增加电极数量可避免双金属U型界面、浇不足及冷隔等缺陷的产生,获得界面结合牢固、均匀平整且过渡层适当的双金属平板件.双金属Cr12MoV钢一侧的淬火和回火组织为回火马氏体 网状共晶碳化物 细小粒状二次碳化物 少量残余奥氏体.双金属的最佳热处理工艺为980℃淬火 230℃回火,其冲击韧性ak值可达25 J/cm2以上,工作层硬度HRC≥62.     

稀有元素添加剂对TiC钢结硬质合金性能影响的研究

本文讨论了稀有元素添加剂对TiC钢结硬质含金性能的影响。试验表明：稀有元素对TiC钢结硬质合金的物理力学性能和烧结工艺性能有很大的影响．把少量稀有元素添加到TiC钢结硬质含金中可使合金中的脆性硬质点减少，孔隙度降低，从而明显地提高合金的横向断裂强度。同时合金的烧结温度区间也有所扩大。     

Metal Alloys for Fusion‐Based Additive Manufacturing

Metal additive manufacturing (AM) is an innovative manufacturing technique, which builds parts incrementally layer by layer. Thus, metal AM has inherent advantages in part complexity, time, and waste saving. However, due to its complex thermal cycle and rapid solidification during processing, the alloys well suit and commercially used for metal AM today are limited. Therefore, it is important to understand the alloying strategy and current progress with materials performance to consider alloy development for metal AM. This review presents the current range of alloys available for metal AM, including titanium, steel, nickel, aluminum, less common alloys (including Mg alloys, metal matrix composites alloys, and low melting point alloys), and compositionally complex alloys (including bulk metallic glasses and high entropy alloys) with a focus on the relationship between compositions, processing, microstructures, and properties of each alloy system. In addition, some promising alloy systems for metal AM are highlighted. Approaches for designing and optimizing new materials for metal AM have been summarized.

     

Mechanical,forming and biological properties of Ti-Fe-Zr-Y alloys prepared by 3D printing

Biomedical Ti-Fe-Zr-Y alloys were prepared by 3D printing on pure titanium substrate. The influences of Zr on mechanical, forming, and biological properties of the alloys were investigated in detail. The results showed that with increasing the Zr addition, the surface roughness, friction coefficient and worn volume decrease at first and then increase, the lowest values obtained at 5.86 at.% Zr addition. The ultimate compression stress and specific strength gradually decrease. The studied alloys have no cytotoxicity. They can promote the early adhesion and proliferation of cells. The eutectic alloy with 5.86 at.% Zr addition has the best ability of apatite deposition, it exhibits a better comprehensive performance among the studied alloys, which is superior to the Ti_70.5Fe_29.5 and Ti-6Al-4 V alloys.     

Temperature sensor based on the Er green upconverted emission in a fluorotellurite glass

The temperature dependence of the green upconverted emission from the two thermally coupled ²H_11/2 and ⁴S_3/2 levels of the Er³⁺ ion in a fluorotellurite glass has been analyzed as a function of the optically active ion concentration in order to check its availability as a temperature sensor. The infrared-to-green upconverted emission have been observed by the naked eyes after a cw laser diode excitation at 800 nm. The fluorescence intensity ratio between the thermally coupled emitting levels as well as the temperature sensitivity has been experimentally obtained up to 540 K. A better behaviour as a temperature sensor has been obtained for the less Er³⁺ concentrated glass with a maximum sensitivity of 54 × 10⁻⁴ K⁻¹ at 540 K, one of the highest found in rare-earth doped transparent materials.     

一种RFID复杂事件语义分析方法研究

复杂事件处理技术是射频识别技术（Radio Frequency Identification,RFID）应用中的重要技术。现有的RFID复杂事件处理模型,例如基于petri网的模型、基于树的模型、基于图的模型、基于自动机的模型,并不能十分有效地解决复杂的RFID应用问题,具体地说,RFID复杂事件的语义分析方面缺乏进一步的研究。针对上述问题,提出了一种RFID复杂事件语义分析方法。该方法,借鉴编译原理中的语义分析技术,为事件增添定义了继承属性和综合属性,同时按照事件之间的关系,定义了三种语义模式,最后通过一个语义解析算法,解析出了特定模式组合的语义信息。实验证实,该方法取得了比较理想的效果。     

加捻对热致液晶聚芳酯初生纤维拉伸性能的影响

热致液晶聚芳酯（TLCP）的特殊化学结构使其具有高强度、高模量、低粘度、易加工等诸多优良特性,且TLCP纤维力学性能对其应用于纺织业具有举足轻重的作用。本论文主要研究加捻对TLCP纤维力学性能的影响,探究其影响机理。研究结果表明：加捻对其力学性能影响很大,TLCP纤维束的强力随着捻度的增加呈先增大后减小趋势。当TLCP纤维束的线密度为52.50 tex,捻度为130Tm时,最大强度为9.14 cN/dtex。未加捻TLCP单纤维的线密度为1.394 tex时,最大强度为11.3cN/dtex。