电沉积Fe-Cr合金研究

三价铬盐的二甲基酰胺（ＤＭＦ）水溶液体系电沉积Ｆe-Cr合金,可获得含Ｃr12%-65%(质量分数）的光亮合金镀层,研究了阴极电流密度,镀液pH值,三价铬盐浓度对镀层分的影响及合金层耐腐蚀性能。     

溶胶—凝胶法制备Al2O3·ZuO2复合陶瓷涂层研究

用溶胶-凝胶(Sol-gel)法以Al(NO3)3·9H2O,ZrOCl2·8H2O为原料,乙醇为溶剂,在不锈钢表面制备了xAl2O3·yZrO2复合陶瓷涂层.研究了基材氧化预处理、溶液纽成、添加剂等对陶瓷涂层组成、性能的影响.结果表明:基材氧化预处理能大大改善涂层与基材的结合强度:涂有xAl2O3·yZrO2陶瓷涂层的材料具有较不锈钢更优良的抗高温氧化性能.     

快速凝固耐热铝合金Al—Fe—Cr—Zr的固结工艺及性能

采用多级快速大装置制取ＲＳＡｌ－Ｆｅ－Ｃｒ－Ｚｒ合金粉末，并用二次挤压等四种工艺固结制备出实验样品。通过Ｘ射线衍射、光学金相、硬度以及拉伸实验等测试手段，研究了该合金的显微组织，热稳定性和低温高温拉伸性能。结果表明，采用二次挤压工艺的样品具有良好的固结状态，而且第二相颗粒细小均匀弥散；ＲＳ／ＰＭＡｌ－Ｆｅ－Ｃｒ－Ｚｒ合金属于较好的耐热铝合系列，合金中的主要析出相有Ａｌ１３Ｃｒ２、Ａｌ３Ｚｒ和Ａｌ３     

Effect of trace Sc and Zr on aging behavior and tensile properties of 2618 alloy

１　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅａｌｕｍｉｎｕｍａｎｄａｌｕｍｉｎｕｍａｌｌｏｙｓａｄｄｅｄｔｒａｃｅｓｃａｎｄｉｕｍｈａｖｅｇｒｅａｔｉｍｐｒｏｖｅｍｅｎｔｉｎｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓ,ｔｈｅｒｍａｌｓｔａｂｉｌｉｔｙ,ｗｅｌｄｂｉｌｉｔｙｅｔｃ［１］．ＳｃａｎｄｉｕｍｉｓｃｏｎｓｉｄｅｒｅｄｔｏｂｅａｈｏｐｅｆｕｌｔｒａｃｅｅｌｅｍｅｎｔｔｏｄｅｖｅｌｏｐａｄｖａｎｃｅｄｗｒｏｕｇｈｔａｌｕｍｉｎｕｍａｌｌｏｙｄｕｅｔｏａｄｉｓｐｅｒｓｅｄｐｈａｓｅＡｌ３Ｓｃｐｒｅｃ…     

冷却速度对Al-8.5Fe-1.3V-1.7Si合金主要相组成的影响

为了解冷却速度对Al-Fe-V-Si合金耐热相的形成规律,采用光学显微镜、X射线衍射仪、透射电镜检测了几种冷却速度条件下的Al-8.5Fe、Al-8.5Fe-1.7Si、Al-8.5Fe-1.3V-1.7Si(质量分数,%)合金的微观组织结构.结果表明:V、Si元素能影响平衡相Al13Fe4的形貌,冷却速度对Al13Fe4的存在起着决定性作用,要消除Al13Fe4相就必须采用大的冷却速度(＞103K/s).在Al-8.5Fe-1.7Si-1.3V合金中全部得到α-Al和Al12(Fe,V)3Si相,冷却速度应大于104K/s.     

钪、锆对Al-Cu-Mg-Fe-Ni系铝合金显微组织与力学性能的影响

通过添加钪,锆,调整铜量,配制实验合金,采用Ｘ射线衍射,透射电镜,扫描电镜,硬度测量,拉伸试验等手段研究了实验合金挤压棒材组织性能,探讨了含钪,锆的Ａｌ－Ｃｕ－Ｍｇ－Ｆｅ－Ｎｉ系合金的强韧化机理。在２６１８铝合金中添加钪,锆使合金的组织性能得到了明显改善,但钪,锆不宜过量。     

锆和稀土元素细化Al-Mg合金铸态组织的机理探讨

采用金相显微镜、扫描电镜和能谱分析等手段研究了在Al-Mg合金中同时添加等量的稀土元素(La,Er)和Zr后合金的铸态组织,发现枝晶网胞尺寸明显减小,晶粒细化,同时有细小的Al3Zr粒子分布于晶内,而Al-RE化合物集中分布于晶界处.存在两种细化机制,生成的Al3Zr质点在凝固过程中起非均质形核的作用,稀土加入引起凝固过程中溶质再分配造成固液界面前沿成分过冷度增大.     

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。     

Decomposition processing and precipitation hardening of rapidly solidified AI-Cr-Y-Zr alloy

Foil powders of AI-5.0Cr-4.0Y-1.5Zr ( % ) were prepared by using a multi-stage atomization-rapid solidification powder-maklng device. The obtained powders were exposed thermally at various temperatures. Variation of microstructures and properties of the alloy powders was investigated by micro-hardness measurement, X-ray diffraction, differantial thermal-analysis, and transmission electron microscopy with energy disperse X-ray analyses. The results show that cubic Al20Cr2Y ( a = 1. 437 nm) and metastable LI2 Al3Zr (FCC, a = 0. 405 1 nm) or equilibrium DO23 Al3Zr ( tetragonal structure, a = 0. 409 1 nm, b = 1.73 0 nm) are main second phases precipitated from supersaturated solid solution of the rapidly solidified foil powders during thermal exposure. The cubic dispersion precipitates prior to the two other Al3Zr type intermetallic phases in the course of the decomposition. Precipitation of incoherent Al20Cr2Y results in softening of foil powder, and coherent LI2 AI3Zr has imensive precipitation strengthening effect. The Al20Cr2Y phase is structurally stable, but it is prone to coarsen and polygonize above 450 ℃. Both Al3Zr type intermetallic phases have much smaller coarsening rate than Al20Cr2Y at temperature higher than 450℃. These two phases are able to keep their fine spherical morphologies up to 550℃, but Al3Zr transforms into DO23 structure from LI2 structure during thermal exposure above 550℃.     

Primary crystallization process of rapidly solidified Al-Ni-Cu-Nd metallic glasses under continuous heating regime

1　INTRODUCTIONManyAl basedamorphous/nanocrystallinealloyscontainingtransitionmetal (TM =Fe ,Co ,Ni,Cu ,etc)andrareearth (RE =La ,Y ,Ce ,Nd ,etc)ele mentshaveanattractivecombinationofmechanicalproperties[13] .InthelasttenyearsawideinterestwasspurredtoresearchprimarycrystallizationofAl richmetallicglasses[4 9] .ThenanophasecompositesofAl TM REsystemcanbeobtainedbyasuitableprocessingcombinationofrapidsolidificationandheattreatment[10 16 ] .Asanimportantwell controlledmethod ,annealin…