FeNiCrAlRE高使用温度耐热合金研制

从Ｆｅ－（８～４０）Ｎｉ（１０～３０）Ｃｒ－（３～８）Ａｌ合金中筛选出３种γ相合金，它们的抗氧化性与ＦｅＣｒＡｌ合金相同，热强性、抗脆化能力和塑性与Ｃｒ２０Ｎｉ８０合金相当，而且有良好的铸造、冷加工和焊接性能，热加工工艺已被掌握。合金生产成本为Ｃｒ２０Ｎｉ８０的１／３，在耐热和电热领域有重要的应用前景。选出了２种γ＋α双相合金，与ＦｅＣｒＡｌ合金相比，其抗氧化性相同，热强性和抗脆化能力略高，塑性稍低，可用于高使用温度耐热结构元件。α相合金塑性很低，但可从它极高的强度和硬度特性开发实际应用。添加稀土元素对发展新合金起关键作用。     

齿轮钢包中喂钛铁芯线工艺研究

齿轮钢２０ＣｒＭｎＴｉ采用包中喂Ｔｉ－Ｆｅ合金芯线工艺效果良好，能显著提高Ｔｉ－Ｆｅ合金的回收率，与炉内加入法相比，Ｔｉ平均回收率由原来３７％提高到８７．９％，节约Ｔｉ－Ｆｅ合金４．３ｋｇ／ｔ，成本下降３２．６４＄／ｔ。     

AuCu20合金的晶体结构对室温加工性能的影响

ＡｕＣｕ２０合金的晶体结构对室温加工性能的影响高敏牛慧玲（北京有色金属研究总院北京１０００８８）杨改英（清华大学）关键词：ＡｕＣｕ２０合金有序相变物理性能１前言本世纪３０年代以来，贵金属及其合金在现代科学和尖端技术领域得到了越来越广泛的应用，成为航空...     

空心电极喷粉生产锰硅合金的试验

本文介绍了采用空心电极喷矿粉工艺生产锰硅合金的试验情况。结果表明，１８００ｋＶＡ矿热炉每炉喷粉料２００－３００ｋｇ，可使产量提高５—２０％，节电１０—２０％，电极消耗降低２５—５０％，产品成本降低２００元／ｔ左右。     

BT20钛合金的工艺特性及锻造与模锻工艺

ＢＴ２０（Ｔｉ－６．５Ａｌ－２Ｚｒ－１Ｍｏ－１Ｖ）钛合金是前苏联航空材料研究院（ＢＨＡＭ）于１９６４年研制成功的一种通用型合金．该合金可用来生产锻件、模锻件、棒材、厚板、薄板和型材等加工产品,在前苏联已列入　ＯＣＴ和ＯＣＴ等有关标准,进行工业化生产,并在飞机结构和发动机上得到应用． 有关ＢＴ２０合金的工艺特性及锻造与模锻工艺方面,已进行了大量的工作［１－３］．现将其作简要介绍,并将其与纯钛和ＢＴ６等钛合金进行对比,评价其可锻性,以供制订合理的ＢＴ２０合金锻造和模锻工艺参考．１确定合金锻造与模锻热…     

低脆性FeCrAlY电热合金的研制

Ｆｅ－１５Ｃｒ－４Ａｌ－Ｙ合金克服了ＦｅＣｒＡｌ合金的高温脆化和４７５℃脆性，热强性和冷加工性也明显改善，ＦｅＣｒＡｌ使用温度高，抗氧化性好等优点则得到保留。还研制了使用温度更高的Ｆｅ－２０Ｃｒ－４Ａｌ－Ｙ和Ｆｅ－２５Ｃｒ－４Ａｌ－Ｙ合金，形成了低脆性合金系列。加入强化元素能进一步提高合金的热强性，用轻稀土元素代替Ｙ则能降低生产成本。合金生产中的工艺困难已经解决，现已投入批量生产。合金用于电热、电阻元件，耐热结构件和耐高温涂层。用它代替Ｎｉ—Ｃｒ系合金可降低元件成本，提高其使用温度和服役寿命。     

冷变形对Inconel X—750改型合金组织性能的影响

研究了在５００～９００℃温度时效不同时间后，合金显微镜硬度变化规律。结果表明，经１０％～２０％冷变形后合金硬度显著提高，而且即使再经７００℃高温长时间时效，形变强化效果也能保持，８００℃时效时，当保时间少于２ｈ的情况下，合金才能保持冷变形强化效果；９００℃时效时，冷变形强化完全消失。     

硬面堆焊复合制造板轧矫直辊研究

采用研制的３４ＣｒＭｏ２ＭｎＶ合金堆焊复合制造２０、５０ｍｍ钢板轧机硬面系列矫直辊，结果表明：较之原５５Ｃｒ辊，使用寿命提高５倍以上，板坯表面质量大为改善。简介了５５Ｃｒ矫直辊的失效机理，高碱度陶质焊剂的配方，以３４Ｃｒ４Ｍｏ２ＭｎＶ堆焊合金的硬度、金相组织以及该合金硬面矫直辊的堆焊复合制造工艺。     

耐磨耐蚀非晶态合金粉末的研究

本文介绍了两种非晶态合金粉末的制备及性能。其中耐磨Ｍ＿（８０）Ｓ＿（２０）非晶粉末具有很高的非晶形成能力，可通过常规氮气雾化法制备；耐蚀ＦＣＰ－３非晶粉未可通过高压水雾法制备。分别采用“枝（胞）晶间距”法和“传热过程多数”法估算出Ｍ＿（８０）Ｓ＿（２０）合金熔体冷凝形成非晶态时的冷却速率为１０￣３～１０￣４Ｋ／ｓ。结合ＸＲＤ和ＤＴＡ分析手段研究了Ｍ＿（８０）Ｓ＿（２０）非晶合金的径向分布函数、结构弛豫、晶化和相变的行为。Ｍ＿（８０）Ｓ＿（２０）晶合金粉末可通过等离子、超音速火焰喷涂获得耐磨性能良好的非晶涂层。ＦＢＳＮ晶态合金粉末可通过球磨工艺制得超微晶合金粉末。     

浅析锌压铸合金质量的影响因素

锌压铸合金自本世纪初问世以来，应用范围日益扩大，广大消费者对其使用性能的要求也不断提高，合金的实物质量已高于相应的标准要求，各生产厂家已为此作出了较大努力。为了控制有害杂质的行为，对其在原料中的含量要求越来越低。为了提高合金的质量，确保其使用性能的改善与稳定，对生产工艺的控制也越来越严。人们不仅已意识到了合金炼制过程中温度和气氛控制的重要性，而且还非常关注造渣剂、熔炼设备、杂质等诸多方面质量影响因素的控制；了解这些也将无疑地有益于生产厂家提高锌压铸合金的产品质量。     

电阻焊接模块新材料

研究了一种用作电阻焊接模具材料的新型TZMC合金、该合金比原用纯钼材料寿命提高5-6倍,产品焊接质量好,可以推广使用。     

Analysis of the mechanism of die soldering in aluminum die casting

A mechanism of soldering of an aluminum alloy die casting to a steel die is proposed. A soldering critical temperature is postulated, at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. The liquid joins the die with the casting upon solidification. The critical temperature is determined by the elements in both the casting alloy and the die material and is equal to the solidus temperature of the resulting alloy. The critical temperature is used to predict the onset of die soldering, and the local liquid fraction is related to the soldering tendency. Experiments have been carried out to validate the concept and to determine the critical temperature for die soldering in an iron-aluminum system. Thermodynamic calculations are used to determine the critical temperature and soldering tendency for the cases of pure aluminum and a 380 alloy in a steel mold. Factors affecting the soldering tendency are discussed, and methods for reducing die soldering are suggested.     

Casting of High Alloy Steels in the Mushy State

In order to broaden the field of application for the innovative thixocasting process, much research is dedicated to the thixocasting of high melting point alloys. The wide property range of modern high alloy steels combined with the productive semi‐solid die casting process opens up new fields of application. The Foundry Institute of the Aachen University has therefore been concentrating on the research of the possibilities and limits of high pressure die casting of high alloy steels in the semi‐solid state. This paper gives an overview of the current work dedicated to thixocasting of steel alloys by a high pressure die casting machine at the Foundry‐Institute of the Aachen University of Technology. In order to understand and describe the material properties in the semi‐solid state, basic test specimens have been investigated. Weak points of tool preheating as well as directional solidification of the produced parts can be controlled by numerical simulation of the temperature distribution inside the dies. In consideration of the outstanding flow properties of semi‐solid steels more complex geometries with accurately defined applications are now being investigated. Extensive metallographical analyses of the pre‐material, the reheated billets and the produced parts have been done to evaluate the viability of the process. The mechanical properties of the specimens outline the outstanding potential of the thixocasting process.     

铝型材挤压成型过程有限元模拟及模具优化设计

应用UGNX建立了平面分流组合模的几何模型,利用有限元软件DEFORM-3D对挤压过程进行有限元模拟,研究了挤压铝合金空心型材时金属的流动情况。模拟结果表明,即便是对称性较好的铝合金窗用光企型材（有一个对称轴）模具,按照常规的设计方法也很难避免金属的流速不均问题,影响型材的成型度。对于绝大多数空心型材来说,其断面往往都是不对称的,仅依靠设计者的经验和判断设计模具是很难避免金属流速不均问题的。而采用有限元模拟的方法,则可以及时发现设计中存在的不足,并通过修改设计方案,达到满意的效果,为设计模具提供科学的依据。     

锌白铜圆线拉伸工艺的改进

针对锌白铜材料的性能特点，结合实际生产中出现的质量问题，对润滑剂及拉模进行了改进。以粘稠润滑剂代替乳化液，并以组合压力模代替普通拉模，不仅改善了拉伸润滑状况，而且节能降耗，缩短生产周期，提高了线材质量。     

Die soldering: Mechanism of the interface reaction between molten aluminum alloy and tool steel

Die soldering is the result when molten aluminum sticks to the surface of the die material and remains there after the ejection of the part; it results in considerable economic and production losses in the casting industry, and is a major quality detractor. In order to alleviate or mitigate die soldering, one must have a thorough understanding of the mechanism by which the aluminum sticks to the die material. A key question is whether the die soldering reaction is diffusion controlled or interface controlled. A set of diffusion couple experiments between molten aluminum alloy and the ferrous die was carried out. The results of the diffusion couple experiments showed that soldering is a diffusional process. When aluminum comes in contact with the ferrous die material, the iron and the aluminum atoms diffuse into each other resulting in the formation of a series of intermetallic phases over the die material. Initially iron and aluminum react with each other to form binary iron-aluminum intermetallic phases. Subsequently, these phases react with the molten aluminum to further form ternary iron-aluminum-silicon intermetallic phases. Iron and aluminum have a great affinity for each other and the root cause of die soldering is the high reaction kinetics, which exists between iron and aluminum. Once the initial binary and ternary intermetallic phase layers are formed over the die material, the aluminum sticks to the die due to the abnormally low thermal conductivity of the intermetallic phases, and due to favorable interface energies between the intermetallic layers and aluminum. The experimental details, the results of the interface reactions, and the analysis leading to the establishment of the mechanism giving rise to die soldering are reviewed discussed.     

Investigation of the effect of structural factors and surface composition on the properties of eutectic silver-copper solders used in vacuum technology

Structural changes that occur in silver-copper solders during their production with the use of new technological processes are considered. Metallography, electron microanalysis (EMA), and Auger electron analysis (AES) have been used to study changes at the contact surface of the material and their effect on the processes of solder flowing. The contents of alloying elements in phase constituents of the alloy have been determined. The composition of films formed on the surface of the material has been found. The data obtained allowed the optimization of the technological process of fabricating solders and increasing the quality of soldering.     

Erosion-oxidation interaction in Ni and Ni-20Cr alloy

The solid-particle erosion of metals and alloys at elevated temperatures is characterized by different mechanisms of material removal, depending on the temperature of exposure, impact velocity, impact angle, and flux rate of the eroding particles. The objective of this article is to delineate the prevalent erosion mechanisms in nickel and a nickel-20 chromium alloy over a large range of temperatures, impact velocities, impact angles, and particle feed rates. For this purpose, a specialized elevated-temperature erosion rig has been utilized. Nickel and a Ni-20Cr alloy have been chosen as the test materials, in view of their substantially different oxidation behaviors. Results from the present study indicate that while the erosion rate generally increases with increasing temperature, an increased particle feed rate causes a reduction in the erosion rate, especially at higher temperatures beyond 650 K. On the basis of a detailed examination of the morphology of the eroded surfaces and the subsurface features beneath the eroded surfaces, four different material removal mechanisms have been identified in the nickel, while only three material removal mechanisms were operative in the Ni-20Cr alloy. Utilizing the aforementioned information, erosion-oxidation (E-O) interaction mechanism maps (herein, termed E-O maps) delineating the regions of dominance of the various erosion mechanisms in an impact velocity-test temperature space have been constructed for Ni and a Ni-20Cr alloy. Finally, the differences in erosion behavior between the Ni and Ni-20Cr alloy have been identified and rationalized.     

半固态铸造技术研究现状与展望

半固态铸造是一种新的材料成形技术，综述了半固态铸造合金的组织变化，坯料制备，充型过程数值模拟和应用等方面的研究成果，同时对我国发展半固态铸造技术得出了若干值得重视的问题。     

Utilisation of silicon rubber to characterise tool surface quality during die compaction

Abstract

A new methodology was developed to observe and measure tool wear and tool surface quality during the die compaction process. The newly developed method is a non-destructive test that relies on silicon rubber to transcribe the inner surface profile of the compaction die. After verification of the method, aluminium and iron alloy powders were compacted to quantify tool wear and tool surface quality with two die materials, tungsten carbide and tool steel. The tool surface quality was quantified by recording surface roughness of the die replicas on a surface profilometer.