挤压铸造合金材料及其工艺性能

挤压铸造(也称液态模锻)是一种加压成形方法,其使用范围和产品性能方面与压铸都有较大区别。文中提出了挤压铸造合金材料的概念,并与压铸对比了对合金材料工艺性能的要求,进一步提出了挤压铸造铝合金的成分范围:挤压铸造对合金材料的铸造和变形工艺性能要求很低,其成分范围涵盖所有变形合金和铸造合金。     

Si元素对Fe-Al基阻尼合金微观组织和内耗性能的影响

制备了含Si量分别为0％、0．6％和1．2％的三种Fe-5．8Al合金,并研究了这三种合金在900℃退火2 h 空冷后的微观组织特征和内耗行为,解释了Si含量及析出相对Fe-Al合金阻尼性能的影响机理,并提出了该系合金的阻尼机制。     

Ag-Cu-Si合金的熔化特性

用ＤＴＡ 法测定Ａｇ － Ｃｕ － Ｓｉ 合金中（ＣｕＡｇｘ）１００ － ｙ － Ｓｉｙ（ｘ ＝ １０ ， ２０ ， ３０ ， ４０ ， ５０ ，７２） 及（ＣｕＳｉ５） － Ａｇ ７ 个特定成份伪二元系的固相线、液相线。结果表明， Ｓｉ 含量对Ａｇ － Ｃｕ合金液相线温度及熔化间隔Δｔ 的影响是显著的。在研究的Ｓｉ 名誉含量０ ～１０ｗｔ％ ， 其液相线呈“Ｖ”型变化。Δｔ 值小对于钎料合金选择和降低Ａｇ 含量是有利的     

Strong and Ductile Non-equiatomic High-Entropy Alloys: Design,Processing, Microstructure,and Mechanical Properties

We present a brief overview on recent developments in the field of strong and ductile non-equiatomic high-entropy alloys (HEAs). The materials reviewed are mainly based on massive transition-metal solute solutions and exhibit a broad spectrum of microstructures and mechanical properties. Three relevant aspects of such non-equiatomic HEAs with excellent strength–ductility combination are addressed in detail, namely phase stability-guided design, controlled and inexpensive bulk metallurgical processing routes for appropriate microstructure and compositional homogeneity, and the resultant microstructure–property relations. In addition to the multiple principal substitutional elements used in these alloys, minor interstitial alloying elements are also considered. We show that various groups of strong and ductile HEAs can be obtained by shifting the alloy design strategy from single-phase equiatomic to dual- or multiphase non-equiatomic compositional configurations with carefully designed phase instability. This design direction provides ample possibilities for joint activation of a number of strengthening and toughening mechanisms. Some potential research efforts which can be conducted in the future are also proposed.     

SLM成形和热处理对AlSi10Mg合金组织与性能的影响

与重力铸造AlSi10Mg合金相比,激光选区熔化成形过程中产生细小的晶粒,在α-Al基体中的粗大块状或针状Si相变为网格状且均匀分布。由于激光选区熔化成形过程中冷却速度较快,形成了过饱和固溶体,其抗拉强度、屈服强度和伸长率分别为483MPa、314MPa和6.43%。经T6处理后,均匀网络状的Si相发生溶解、断裂,并且聚集长大为圆整钝化的不规则形状,以及成细小弥散分布的Si相,合金的抗拉强度和屈服强度降低至208MPa、167MPa,伸长率提高至10.37%。     

Si元素对Fe-Al基阻尼合金微观组织和内耗性能的影响

制备了含Si量分别为0％、0．6％和1．2％的三种Fe-5．8Al合金，并研究了这三种合金在900℃退火2h空冷后的微观组织特征和内耗行为，解释了Si含量及析出相对Fe-Al合金阻尼性能的影响机理，并提出了该系合金的阻尼机制。     

钛合金熔炼技术的进展

钛及钛合金具有密度低、比强度高、高温性能好及耐腐蚀性能好等优点,逐渐成为一种优异的航空航天结构材料.本文概述了钛合金熔炼技术的发展现状.     

Relationship Between the Processing Parameters and the Properties of Semi-solid Processed Al Alloys

Relationship between the processing parameters and the properties of semi-solid processed Al alloys were studied and microstructure and mechanical properties of semi-solid processed Al parts for automobile application as a function of processing parameters were compared with those of die-cast parts and forged parts. In addition, the locations for the gate during the semi-solid processing were varied to elucidate the distribution of micro-porosities and resulting mechanical properties and the T6 heat treatment on the semi-solid processed part was performed so that the effect of heat treatment on the improvement of mechanical properties could be evaluated in terms of tensile strength, wear properties, etc. Microstructure of semi-solid processed Al part did not show any noticeable micro pores as compared to the microstructure of die-cast part. T6 heat treatment on A319 alloys has greatly improved the hardness as well as the wear resistance. Semi-solid processed A319 part showed slightly higher hardness val     

Effect of Small Amount of Manganese on the Interdiffusivities in Fe-Al Alloys

The ability to weld aluminum and steel sheets depends strongly on the formation of intermetallic phases; a process that is, in turn, controlled by the interdiffusion of iron and aluminum across the welded interface. Understanding the interdiffusion behavior, and how it is influenced by tertiary elements such as manganese, will allow for better prediction of the properties of the spot weld. Hence, interdiffusion coefficients and activation energies for interdiffusion were determined in the α solid solution and B2 intermetallic phases of Fe-Al alloys in the presence of 1.5-2 at.% manganese with pseudo-binary diffusion couples investigated at 900-1095 °C. The interdiffusion coefficients in α were found to increase in the presence of Mn at all temperatures compared with those reported in the binary Fe-Al alloys. The activation energies for interdiffusion in α are correspondingly lower than those in the binary Fe-Al alloys. The increase in the main interdiffusion coefficients in the presence of Mn indicates that diffusional interactions between Fe and Al are increased in the presence of Mn. The expected increase in diffusional interactions of Fe and Al are found to be consistent with the thermodynamic interactions between Fe and Al in the binary Fe-Al and ternary Fe-Al-Mn system as estimated from the literature. The presence of Mn is found to decrease the solubility of Al in the α solid solution, which, in turn, is expected to decrease the growth rate of the intermetallic at the interface between steel and aluminum.     

Induction Skull Melting of Titanium and Other Reactive Alloys

Along with discussing the development history of the induction-slag process for melting titanium, zirconium, and other reactive alloys, this paper examines a recent modification to the process which eliminates calcium fluoride slag, producing inclusion-free metal. Also considered are the application and commercialization of this technology. In addition, some of the mechanical properties and structure of induction skull melted Ti-6Al-4V, including very good fatigue strengths, are reported.     

Si对Zn-Al合金性能的影响

研究了Ｓｉ对ＺｎＡｌ２７Ｃｕ２Ｓｉｘ和ＺｎＡｌ２７Ｍｇ０．０２Ｓｉｘ两类合金力学性能和耐磨性的影响。研究发现,随着Ｓｉ含量的增加,这两类合金的抗拉强度、硬度和耐磨性都提高,而耐塑性下降;含Ｓｉ量在４％左右时,这两类合金的抗拉强度都达到最大值,ＺｎＡｌ２７Ｓｉ４Ｍｇ０．０２和ＺｎＡ２７Ｓｉ４Ｃｕ２合金的抗拉强度分别为４００ＭＰａ和３６７ＭＰａ;当Ｓｉ量为２％～４％时,这两类合金的耐磨性最好。     

钛及高温合金的冷炉床熔炼

综述了冷炉床熔炼的发展历史、特点、炉子的结构和工作原理以及电子束和等离子体两种熔炼方式用于熔炼纯钛和Ｔｉ－６Ａｌ－４Ｖ的各自优点。     

Mg-Zn-Y-Nd-Zr合金的显微组织、织构、力学性能

对Mg-Zn-Y-Nd-Zr合金的显微组织和力学性能进行了研究。结果表明,Nd元素的加入部分取代了W相（Mg₃Zn₃Y₂）中的Y元素,形成了新的第二相Mg₃Zn₃(Y, Nd)₂。热挤压后观察到由细小的等轴再结晶晶粒和粗大的细长未再结晶晶粒组成的典型双峰结构。Nd元素的加入促进了热挤压过程中的动态再结晶,随着Nd含量的增加,动态再结晶率增加,挤压态合金的整体织构强度减弱。Nd的加入细化了晶粒并改善了合金的力学性能。添加0.5%（质量分数）Nd时,挤压态合金表现出高强度和高塑性的良好结合：屈服强度为362 MPa,极限抗拉伸强度为404 MPa,延伸率为10.2%。时效处理后合金的抗拉伸强度进一步提高,峰值时效极限抗拉伸强度可达421 MPa。合金的高强度主要归功于超细再结晶晶粒和析出强化。     

激光工艺参数对选区激光熔化钽微观组织和力学性能的影响

研究了单、双层扫描策略和能量密度（246~640 J/mm³）对选区激光熔化钽显微组织及力学性能的影响。采用扫描电子显微镜和电子背散射衍射对选区激光熔化钽的显微组织进行表征,并对其显微硬度和拉伸性能进行检测。结果表明,选区激光熔化钽显微组织由明显向上生长的柱状晶构成,双层扫描后的钽具有更细的晶粒尺寸。随着输入能量密度的提高,选区激光熔化钽的强度、显微硬度和塑性均具有明显的上升趋势。此外,双层扫描工艺可进一步提高材料密度,且在保留强度的基础上,增强材料塑性。在能量密度为640 J/mm³（双层扫描）时,金属钽性能最优,显微硬度、极限抗拉伸强度及延伸率分别为2307 MPa,527 MPa和11.4%。     

合金元素及制备工艺对1XXX系铝合金组织及性能的影响

通过直接激冷铸造（DCC）与双辊铸轧（TRC）方法生产了具有不同Fe、Si、Cu和Mn含量的1XXX系铝合金坯料,随后通过均匀化、热轧、冷轧和退火等加工工艺制备了厚度为13 μm的铝箔。结果显示,铸造工艺对铝箔强度影响较小,双辊铸轧引入的较细第二相有利于铝箔塑性。在580 ℃以上进行均匀化处理可细化直接激冷铸造铸锭的粗大晶界金属间化合物,并使其在后续热轧中破碎为小颗粒。因Cu溶质原子可提高加工硬化速率,添加Cu元素的效果优于添加Fe、Si和Mn元素。中间退火时铝箔厚度对力学性能有显著影响,这和厚度与晶粒尺寸之间的比值有关。室温储存会导致较薄铝箔的力学性能下降,这与大应变后发生的回复机制有关。     

γ-TiAl基合金机械性能的研究发展

对国内外基于力学模型的γ-TiAl合金的弹性和塑性性能与其微结构的关系的研究进展进行了详细的论述。同时，概述了作者运用细观力学的方法对TiAl合金的弹性和塑性性能的主要研究工作，指出了γ-TiAl合金的研究和发展方向。     

关于熔炼Cu-Zn合金ZnO中毒的研究

分析了熔炼Cu-Zn合金造成Zn0中毒的原因,阐述了中毒的症状,提出了治疗和预防的方法和措施,杜绝了中毒事件的再发生,保证了生产的顺利进行.     

Fe-C-Si合金感应熔炼的质量控制

探讨了碳素铸钢和铸铁在感应熔炼中的冶金特性,导出了C-Si浓度与平衡温度的修正的平衡方程式。提出了控制熔炼质量的基本模型和制定冶金熔炼制度的要求.     

熔炼铀和铀合金用涂层研究进展

铀和铀合金用涂层不同于通常的耐高温涂层，不仅要求具有耐高温和抗热震，还要求涂层与基体和熔体之间具有化学稳定性。分析了熔炼过程中的铀和铀合金的碳污染源和污染机理。表明炉内的CO和涂层的缺陷面积是熔体碳污染的主要来源，而熔体的碳污染对涂层缺陷面积更敏感，并指出了涂层的设计要求。不同涂层材料体系和制备方法的比较表明：单层涂层不能满足高性能高质量铀和铀合金熔炼的要求；内层为阻挡层（碳化物或难熔金属W，Nb，Mo等），外层为Y2O3的复合涂层，能够满足高温铀合金的熔炼要求，是铀和铀合金用涂层的发展趋势。