快速凝固铝锂合金粉末特性对其挤压材组织和性能的影响

采用一种快速冷凝装置研制了Ａｌ－２．５Ｌｉ－１．６Ｃｕ－１．２Ｍｇ－０．２Ｚｒ合金粉末及合金。探讨了合金粉末特性及其对快速凝固铝锂合金微观组织和力学性能的影响。采用片状粉末制备的这种快速凝固铝锂合金，具有较好的强塑性综合力学性能。     

快速凝固耐热Al－Fe－MRE合金粉末的制备及其特性研究

研究了快速凝固铝铁混合稀土高温合金粉末的制备及其特性，用氩气及氦气超音速雾化制得的粉末呈球形，获得的冷却速率为５×１０３～７×１０６Ｋ／ｓ。冷却速率主要受粉末尺寸影响，同样尺寸的粉末以氦气作冷却介质时获得的冷却速率较高。粉末尺寸越小，组织越细，力学性能越好。     

快速凝固耐热Al—Fe—MRE合金粉末的制备及其特性研究

研究了快速凝固铝铁混合稀土高温合金粉末的制备及其特性，用氩气及氦气超音速雾化制得的粉末呈球形，获得的冷却速率为５×１０＾３－７×１０＾６Ｋ／ｓ。冷却速率主要受粉末尺寸影响，同样尺寸的粉末以氦气作冷却介质时获得的冷却速率较高。粉末尺寸越小，组织越细，力学性能越好。     

过共晶铝硅合金的研究进展

文章从变质处理、快速凝固、超声波处理、半固态处理等方面对过共晶铝硅合金组织的影响和力学性能的改善进行了介绍,为过共晶铝硅合金的研究人员提供参考。     

快速凝固低密Al－Li合金组织、性能和断裂过程的研究

采用快速凝固氩气雾化法制备低密Ａｌ－Ｌｉ合金粉。经粉末包铝套，真空除气后热挤压成材。探讨了粉末颗粒的显微组织及其氧化情况；用透射电镜和动态扫描电镜研究了低密Ａｌ－Ｌｉ合金的微观组织和拉伸断裂过程。     

快速凝固低密Al—Li合金组织、性能和断裂过程的研究

采用快速凝固氩气雾化法制备低密Ａｌ－Ｌｉ合金粉。经粉末包铝套、真空除气后热挤压成材。探讨了粉末颗粒的显微组织及其氧化情况；用透射电镜和动态扫描电镜研究了低密Ａｌ－Ｌｉ合金的微观组织和拉伸断裂过程。     

几种快速凝固Al—Li合金的研究

采用氩气雾化快速凝固法(RS)制备了两个系列(Al-Cu-Li、Al-Cu-Li-Mg系)、五种成份的合金。研究了合金的成份、粉末粒度、成型工艺参数及热处理制度对合金力学性能的影响,并对各种合金的微观组织做了研究,此外,还观察、分析了几种合金的拉伸断口。     

快速凝固技术在铝基合金材料中的应用

介绍了快速凝固技术的特点以及快凝铝基合金材料的发展现状,综述了快速凝固技术在铝基合金材料中的应用以及铝基晶态合金、铝基准晶合金、铝基非晶合金的发展现状。最后指出,快速凝固技术需要进一步完善工艺,降低成本,实现量产;需要优化合金成分,加强多元系合金快凝过程的理论研究以及计算机模拟在铝基合金材料快凝过程中的模拟应用。     

高速凝固铝-锂系合金简介

高速凝固粉末冶金铝合金及喷射成形铝合金是高技术新材料,在交通运输装备制备特别是航空航天器制造中获得了较为广泛的应用。用高速凝固粉末制备的工业铝合金有：铝-锂合金、铝-铁合金、铝-硅合金、2×××系合金、7×××系合金等。本文着重介绍铝-锂系合金。     

高能球磨稀土高硅铝合金粉末性能表征

对快速凝固法制备得到的Al-20Si-0.35RE合金进行不同时间的高能球磨, 然后对球磨后的粉末进行多次热压变形, 采用XRD, ESEM以及TEM等表征变形前后合金粉末的显微组织, 并对变形后合金的导电性能进行了研究. 研究发现快速凝固Al-20Si-0.35RE合金粉末的显微组织主要由细小的Al-Si固溶体(0.3～0.5 μm)、初晶硅、稀土铝硅化合物(0.16～0.3 μm)组成; 随着球磨时间延长, 颗粒粒径显著减小; 经过多次热压变形后合金晶粒显著细化, 晶格畸变减小, 位错钉扎稀土化合物, 形成类似表面渗流效应, 合金导电率提高至70%IACS.     

快凝AlCrYZr合金挤压成形与组织性能

添加Y合金化、配制AlCrYZr合金,采用金相、X射线衍射、透射电镜、扫描电镜、力学拉伸实验等研究手段,研究了快速凝固AlCrYZr合金粉末挤压成形工艺以及其对组织性能的影响。结果表明,实验合金中主要第二相为Al₂₀Cr₂Y(立方,a=1.44nm)和Al₃Zr;挤压成形时提高挤压比,降低挤压温度,有利于改善粉体结合状况,得到Ll₂Al₃Zr质点,同时细化Al₂₀Cr₂Y质点,使合金获得动态回复组织,从而使合金具有良好的低温、高温强度和塑性。     

JPMA awards 2012

Abstract

This communication reports work completed on the extrusion of powder compacts prepared from rapidly solidified Al–10 Mg powder. It is shown that mechanical properties of the extrudate are related to the temperature compensated strain rate obtaining during the extrusion process. Pressure requirements are much lower than are necessary for the extrusion of cast products of Al–7Mg and Al–5Mg and the corresponding increase in heat generation considerably widens the extrusion limits. In the as-extruded condition, the properties are comparable with a peak aged conventional 7050 alloy but the Al–10Mg is extremely unstable and requires an aging treatment to correct this instability. It is concluded that improvement in this alloy system would be obtained either by decreasing the Mg content or by developing a lower %Mg ternary alloy. PM/0280     

以机械合金化新工艺制造弥散强化铝镁合金

把纯铝粉和铝-镁合金粉与炭黑或有机试剂（如甲醇、硬脂酸等）在高能球磨机内研磨,获得机械合金化粉末。将这种粉末冷等静压密实,然后在820°K下挤压,挤压比为26:1,最后制得合金棒材。这种棒材的机械性能检验结果表明,用机械合金化新工艺制造的弥散强化铝-镁合金,机械性能优良。例如54号合金,其机械性能是,σ_b519—529MN/m2,σ_0.2510—519MN/m2,δ4—6%,Ψ9-14%。实验结果还表明,采用这种新工艺制造的铝-镁合金,与铸造铝-镁合金相比,它的机械性能有很大的改善和提高。特别是在573°K温度下经100小时退火后,其极限抗张强度下降得很小或完全不下降。因此这类合金作为一种结构材料使用将会有很大的潜力。     

The microstructures and properties of an al- 12 wt pct

A new process for producing rapidly solidified bulk alloys was developed based on the hammer- and-anvil concept. In the process, an A1-12 wt pct Si alloy slab was built up layer by layer and then hot worked to get a solid and integral sheet. The oxygen content of the layer-deposited alloy is less than the typical value of powder metallurgy (PM) alloys by one order, and the cooling rate can reach 10⁴ K/s, which is higher than that of the spray deposition process. In comparison with the ingot-processed Al-12 wt pct Si alloy, layer-deposited alloy exhibits su- perior mechanical properties. This is attributable to the fine and uniform silicon-particle distri- bution which not only brings on dispersion hardening effect but also raises the elongation and fracture strain. The mechanisms responsible for this enhancement were discussed in terms of particle size and effective volume fraction.     

Mechanical milling of gas-atomized Al-Ni-Mm (Mm = misch metal) alloy powders

Al-14Ni-14Mm (Mm = misch metal) alloy powders rapidly solidified by the gas atomization method were subjected to mechanical milling (MM). The microstructure, hardness, and thermal stability of the powders were investigated as a function of milling time using X-ray diffraction (XRD), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) methods. In the early stages of milling, a cold-welded layer with a fine microstructure formed along the edge of the milled powder (zone A). The interior of the powder remained unworked (zone B), resulting in a two-zone microstructure, reminiscent of the microstructures in rapidly solidified ribbons containing zones A and B. With increasing milling time, the crystallite size decreased gradually reaching a size of about 10 to 15 nm and the lattice strain increased reaching a maximum value of about 0.7 pct for a milling time of 200 hours. The microhardness of the mechanically milled powder was 132 kg/mm² after milling for 72 hours and it increased to 290 kg/mm² after milling for 200 hours. This increase in microhardness is attributed to a significant refinement of microstructure, presence of lattice strain, and presence of a mixture of phases in the alloy. Details of the microstructural development as a function of milling time and its effect on the microhardness of the alloy are discussed.     

快速凝固粉末冶金Al－Si－Cu－Mg合金的组织和性能

本文详细论述了快速凝固Ａｌ－１８．６Ｓｉ－４．３４Ｃｕ－０．６６Ｍｇ合金的制备工艺，研究了这种高硅铝合金的力学性能与组织结构的关系。实验结果表明：快速凝固Ａｌ－Ｓｉ－Ｃｕ－Ｍｇ合金的强度、硬度和塑性明显提高，固溶时效处理后的室温拉伸强度高达４３０ＭＰａ。随着试验温度的升高，其拉伸强度下降，但在２００℃时。бｂ能保持在３７０ＭＰａ。Ａｌ－Ｓｉ合金这样优良的高温热稳定性是一般常规高强铝合金难以达到的。     

Mechanical milling of gas-atomized Al−Ni−Mm (Mm=misch metal) alloy powders

Al−14Ni−14Mm (Mm=misch metal) alloy powders rapidly solidified by the gas atomization method were subjected to mechanical milling (MM). The microstructure, hardness, and thermal stability of the powders were investigated as a function of milling time using X-ray diffraction (XRD), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) methods. In the early stages of milling, a cold-welded layer with a fine microstructure formed along the edge of the milled powder (zone A). The interior of the powder remained unworked (zone B), resulting in a two-zone microstructure, reminiscent of the microstructures in rapidly solidified ribbons containing zones A and B. With increasing milling time, the crystallite size decreased gradually reaching a size of about 10 to 15 nm and the lattice strain increased reaching a maximum value of about 0.7 pct for a milling time of 200 hours. The microhardness of the mechanically milled powder was 132 kg/mm² after milling for 72 hours and it increased to 290 kg/mm² after milling for 200 hours. This increase in microhardness is attributed to a significant refinement of mcirostructure, presence of lattice strain, and presence of a mixture of phases in the alloy. Details of the microstructural development as a function of milling time and its effect on the microhardness of the alloy are discussed.     

Book Review

Abstract

Currently available compaction-ready aluminium powders enable sintered preforms to be readily produced by the powder metallurgy route. Aluminium bearing materials with good sliding properties can be produced by sintering-in abrasion-resistant particles or by using alloy powders with homogeneously distributed lead additions. Reactively ground and mechanically alloyed granulates with dispersoid particles of oxides, carbides, and inter-metallic compounds provide high-temperature PM materials with improved properties. New techniques for powder production provide aluminium alloy powders with extraordinary metallurgical effects within the particles and controlled properties. The consolidation of rapidly solidified aluminium alloy powders into high-strength PM semiproducts has considerably enlarged the potential of aluminium powder metallurgy. The aims of numerous worldwide development projects in powder metallurgy are to improve conventional aluminium alloys and develop new alloys which cannot be produced by the . traditional melting route. PM/0253     

TZM合金的研究现状

TZM合金是目前广泛应用的一种高温钼合金,具有高熔点、抗腐蚀、力学性能优异等优点,被广泛应用于军工、航天和高温结构件等领域。目前TZM合金的制备方法主要有：电弧熔炼法和粉末冶金法。TZM合金的强化机理有：合金元素固溶强化、第二相强化、形变强化。本文还对TZM合金在性能方面的提高所做的研究进行了介绍,并对TZM合金的发展提出了看法。     

添加羰基铁粉提高铁基合金烧结密度的研究

在Ｆｅ－Ｎｉ－Ｃｕ－Ｍｏ－Ｃ系合金中添加羰基铁粉，改善了粉料的压制性能和粉坯的烧结性能。以钢模成形、一次烧结工艺制造的合金，密度达７．５２ｇ／ｃｍ＾３，相对密度９５．２％，提高了制品的力学性能。