复合变质对AlSi7Mg合金组织和性能的影响

通过在铸造ＡｌＳｉ７Ｍｇ合金中加入一种新型复合变质剂，研究其对合金力学性能和组织的影响，并采用透射电子显微镜（ＴＥＭ）研究合金在时效过程中组织的变化。结果表明：采用此新型变质剂可有效提高铸造ＡｌＳｉ７Ｍｇ合金的力学性能。合金经５３５℃×６ｈ固溶化处理和１５０℃×６ｈ时效处理后，其σｂ达到３５１．７ＭＰａ，δ达７．７９％。经ＴＥＭ分析，采用此变质剂处理的铸造ＡｌＳｉ７Ｍｇ合金在时效过程中不仅会产生Ｍｇ２Ｓｉ相，而且发现了一种新的时效强化相。通过分析，认为该相的析出过程与Ｍｇ２Ｓｉ相似，且其析出温度要较Ｍｇ２Ｓｉ相略低。由于此新强化相的析出使得合金在较低温度时效时即可获得较好的强化效果，使合金在Ｔ５状态下即可获得高的综合力学性能     

喷射沉积Al—2.15Li—1.28Mg—1.26Cu—0.10Zr合金的拉伸断裂行为

采用新型的喷射沉积工艺制备了Ａｌ２．１５Ｌｉ１．２８Ｍｇ１．２６Ｃｕ０．１０Ｚｒ合金，对其不同时效状态的拉伸性能及断裂行为进行了研究。实验结果表明，喷射沉积ＡｌＬｉ合金经１９０℃、２０ｈ时效后达到峰时效状态，此时材料的综合性能最优（σｂ＝５２８ＭＰａ，σ０．２＝４２０ＭＰａ，延伸率为１２％）。固溶淬火态实验合金拉伸断口为完全穿晶韧窝型。时效态合金的断裂方式为穿晶和沿晶混合型。随时效时间的延长，沿晶断裂的比例增加。实验合金沿晶断裂的原因是位错的共面滑移、晶界无析出区和晶界平衡相的析出     

退火工艺对Al-Mg-Sc-Zr合金组织与性能的影响

研究了退火温度和退火时间对含微量Ｓｃ和Ｚｒ的Ａｌ５Ｍｇ合金的显微组织和力学性能的影响。结果表明：该合金在热轧—冷轧后１３０℃,３ｈ退火处理可获得最佳的力学性能,σ０．２＝３０８ＭＰａ,σｂ＝４０６ＭＰａ,δ＝１５％;退火过程中,由于Ａｌ３（Ｓｃ,Ｚｒ）第二相对位错和亚晶界的钉扎作用,合金中依次发生不同程度的回复和部分再结晶。     

ZL210A高强度铸造铝合金的研制

研制了一种新型的Ａｌ－Ｃｕ系高强度铸造合金材料。通过对合金元素及含量的优化设计、晶粒细化剂、ＳＭＴ熔炼工艺和热处理工艺等方面的研究，使合金获得优良的机械性能（σｂ＝４００￣５００ＭＰａ，δ＝３％￣６％）。新合金放宽了对Ｆｅ，Ｓｉ有害杂质的限量，具有很高的经济价值和使用价值。     

Zn,Al对Mn—Cu减振合金减振性能的影响

研究了合金元素Ｚｎ、Ａｌ对新型减振降噪（高阻尼）铸造ＭｎＣｕ合金Ｍｓ点、减振性能及力学性能的影响,重点讨论了合金成分与减振性能ＳＤＣ及力学性能的关系。开发了高阻尼、高强度锰铜基阻尼合金ＺＭｎＤ１Ｊ,最优成分为Ｍｎ５０％、Ｚｎ５％、Ａｌ２％、余量Ｃｕ。典型性能：ＳＤＣ＝４４．５％,σｂ＝６７８ＭＰａ,δ＝２４．１％。ＭｎＣｕ系新型高阻尼功能材料的减振能力很高,同时力学性能可达ＺＧＤ３４５５７０的水平,可做结构材料使用。     

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。     

喷射沉积Al-3．8Li-0．8Mg-0．4Cu-0．13Zr合金的显微组织与拉伸性能

采用新型的喷射沉积快速凝固工艺制备了Ａｌ３．８Ｌｉ０．８Ｍｇ０．４Ｃｕ０．１３Ｚｒ合金，并对合金的显微组织与拉伸性能进行了实验研究。实验结果表明，沉积态合金组织为细小、均匀的等轴晶，晶粒尺寸大多在５～２０μｍ范围内。经热挤压后合金组织中的晶粒呈“砖块”状或“竹节”状形貌特征，晶界上破碎的氧化物很少。时效析出不规则形状的δ′相粒子和球壳状β′δ′复合沉淀相。δ′粒子的粗化速度较快，δ′粒子间距随时间增大的趋势不明显。喷射沉积ＡｌＬｉ合金短时间时效（１９０℃，１０ｈ）即可达到峰时效状态，此时材料的综合性能最优（σｂ＝５３４ＭＰａ，σ０．２＝４８０ＭＰａ，延伸率为１０％）。与粉末冶金ＡｌＬｉ合金相比，材料的塑性明显改善而强度相当。     

Al-Mg-Si系挤压合金的自然时效和人工时效特性

较系统地研究了ＡｌＭｇＳｉ系（即６ｘｘｘ系）合金（主要以６０６３，６０６１，６００５和６３５１等挤压合金为代表）的自然时效和人工时效的硬化特性，为优化工艺制度提供了理论依据。     

热处理工艺对AlSi7.0Mg0.3和AlSi7.0Mg0.3Sr合金组织的影响

研究了热处理工艺对定向凝固条件下ＡｌＳｉ 合金共晶组织的影响。通过多级长时间的固溶处理及回火处理,ＡｌＳｉ７－０Ｍｇ０－３０ 和ＡｌＳｉ７－０ Ｍｇ０－３Ｓｒ 合金中的共晶体体积分数在较快冷却速度时要比慢速冷却时的高,而共晶体中硅粒子的体积分数则有较大幅度的降低。经过热处理后,不同凝固条件下的ＡｌＳｉ 合金的共晶硅粒子的平均截面积、平均自由间距与形状系数都较铸态时有较大的提高,而共晶硅粒子的细化度则有明显的减少。即使经过长时间的热处理,加入微量锶的影响仍然存在。     

粉末热锻Al－Si合金

研究了Ａｌ－Ｓｉ合金粉末热锻密实工艺和合金性能。结果表明，当合金含硅量不超过３０％时，锻坯的密度可达到理论密度的９９％以上。合金组织中初晶硅分布均匀，没有针状或大块片状组织出现。添加Ｃｕ、Ｍｇ的Ａｌ－１０Ｓｉ－２Ｃｕ－１Ｍｇ和Ａｌ－１５Ｓｉ－２Ｃｕ－１Ｍｇ合金性能比相应的Ａｌ－Ｓｉ二元合金明显提高，拉伸强度分别达到２８４～３２４ＭＰａ和３０４～３３３ＭＰａ，布氏硬氏１２４～１２８和１２２～１２４     

镍和锰对Al-Si-Cu-Mg合金凝固组织及时效硬化的影响

采用DSC差热分析及急冷试验方法并辅以微区成分分析 ,探讨了Ni和Mn对Al Si Cu Mg四元合金凝固组织、凝固过程及时效硬化特性的影响。Ni的加入量达 4%以上时 ,在组织中将形成初晶型Al Ni Cu三元化合物和共晶型Al Ni Cu三元化合物 ,若同时添加Mn ,则还会结晶出共晶型的Al Si Cu Ni Mn五元化合物 ;Ni和Mn的加入可以加快Al Si Cu Mg合金的时效硬化速度 ,同时又可推迟过时效现象的出现 ,有利于合金耐热性的提高。     

Effect of Be on aging behavior of an Al-Si-Cu-Mg cast alloy

The effect of Be addition on the aging behavior of UNS 03370 (Al11Si3Cu0.3Mg) was investigated by micro-hardness measurement, differential scanning calorimetry (DSC) and transmission electron microscope (TEM) analysis. Age hardening analysis shows Be additions to an Al11Si3Cu0.3Mg alloy accelerates the age hardening rate and increases the peak hardness by 15 HV during aging at 160°C. DSC shows that Be additions lead to an endothermic peak corresponding to the dissolution of Gunier Preston zones (GP I) disappear with exothermic peaks corresponding to precipitation of GP II zones and the λ′ and/or ϑ′ phases shift to low temperature. DSC and TEM analyses show that GP II zones are more effective than λ′ and/or θ′ on hardening the alloy, and Be addition increases the homogeneous nucleation density of GP II zones. The possible Be atoms participating in the precipitation process during aging and the high Be-vacancy binding energy can explain the effect of Be on aging behavior of Al11Si3Cu0.3Mg alloy.     

RECIPROCATING EXTRUSION OF IN SITU Mg_2Si REINFORCED Mg-Al BASED COMPOSITE

M92Si reinforced Mg-Al based composite with high amount o/silicon was prepared by permanent mould casting, and then extruded by reciprocating extrusion （RE） after the composite was processed by homogenization heat treatment. The effect of RE processing on the morphology and size of M92Si and the mechanical properties of the com- posite were investigated, to develop new ways to refine the M928i phase and improve its shape. The result showed that RE was very useful in refining the M92Si phase. The more the RE processing passes, the better the refining effect would be. Moreover, the uniform distribution of M928i phases would be more in the composite. After the composite was processed by RE for 12 passes, most M92Si phases were equiaxed, with granular diameter below 20 μm, and distributed uniformly in the matrix of the composite. The mechanical properties of the composite could be increased prominently by RE processing, and were much higher than that in the as-cast state. As the temperature rises, the tensile strength is reduced. For the composite RE processed for 12 passes, the tensile strength, yield strength, and elongation are 325.9 MPa, 211.4 MPa, and 3.3% at room temperature, whereas, 288.2 MPa, ,207.7 MPa, and 7.8%, respectively, at 150℃. In comparison with the properties at room temperature, the tensile strength and yield strength are high and only decrease by 11.6% and 1.8% at 150℃. The M928i reinforced Mg-Al based composite possesses good heat resistance at 150℃. The excellent resistance to effect of heat is attributed to the high melting tempera- ture and good thermal stability of fine Mg2Si phases, which are distributed uniformly in the composite, and effectively hinder the grain boundary gliding and dislocation movement.     

INFLUENCES OF MICRO ALLOY AND HEAT TREATMENT PROCEDURE ON THE HARDENING OF DJ108TI ALLOY

１．ＩｎｔｒｏｄｕｃｔｉｏｎＭａｎｙｍｅｔａｌｌｕｒｇｉｓｔｓｈａｖｅｓｔｕｄｉｅｄｈｏｗｔｏｇｅｔｅｌｅｃｔｒｏｌｙｔｉｃｂｉｎａｒｙａｌｌｏｙｓ,ｓｕｃｈａｓＡｌＳｉ,ＡｌＴｉａｎｄＡｌＭｎｅｃｔ．ｉｎａｌｕｍｉｎｕｍｅｌｅｃｔｒｏｌｙｚｅｒ〔１,２〕．Ｇ．Ｑ．ＹａｎｇａｎｄＸ．Ｑ．Ｇｕｅｔｃ．ｐｒｏｄｕｃｅｄＡｌＳｉ（２０５％）Ｔｉ（０２５％）Ｆｅ（０３０％）ｍｕｌｔｉｃｏｍｐｏｎｅｎｔａｌｌｏｙｔｈｒｏｕｇｈｄｉｒｅｃｔｌｙｅｌｅｃｔｒｏｌｙｚｉｎｇｂａｕｘｉｔｅｉｎ…     

RECIPROCATING EXTRUSION OF IN SITU Mg2Si REINFORCED Mg-A1 BASED COMPOSITE

Mg2Si reinforced Mg-Al based composite with high amount of silicon was prepared by permanent mould casting, and then extruded by reciprocating extension (RE) after the composite was processed by homogenization heat treatment. The effect of RE processing on the morphology and size of Mg2Si and the mechanical properties of the composite were investigated, to develop new ways to refine the Mg2Si phase and improve its shape. The result showed that RE was very useful in refining the Mg2Si phase.The more the RE processing passes, the better the refining effect would be. Moreover,the uniform distribution of Mg2Si phases would be more in the composite. After the composite was processed by RE for 12 passes, most Mg2Si phases were equiaxed, with granular diameter below 20 μm, and distributed uniformly in the matrix of the composite. The mechanical properties of the composite could be increased prominently by RE processing, and were much higher than that in the as-cast state. As the temperature rises, the tensile strength is reduced. For the composite RE processed for 12 passes, the tensile strength, yield strength, and elongation are 325.9 MPa, 211.4 MPa,and 3.3% at room temperature, whereas, 288.2 MPa, 207.7 MPa, and 7.8%, respectively, at 150° C. In comparison with the properties at room temperature, the tensile strength and yield strength are high and only decrease by 11.6% and 1.8% at 150°C. The Mg2Si reinforced Mg-Al based composite possesses good heat resistance at 150° C. The excellent resistance to effect of heat is attributed to the high melting temperature and good thermal stability of fine Mg2Si phases, which are distributed uniformly in the composite, and effectively hinder the grain boundary gliding and dislocation movement.     

Al−Si−Mg−Er合金的热稳定性和析出相的显微组织

采用显微硬度计和透射电镜研究Er元素对热处理Al?Si?Mg合金显微硬度和析出行为的影响.作为对照,同时研究人工时效前引入自然时效对合金硬度和析出行为的影响.研究结果表明,过时效Al?Si?Mg?Er合金的热稳定性与析出相的平均尺寸密切相关.未引入自然时效时,Al?Si?Mg?Er合金中 β'相的平均尺寸小于Al?Si...     

基于人工神经网络与遗传算法的Al-Mg-Si系合金抗拉强度预测模型

为了研究Al-Mg-Si系合金热处理制度和合金成分对力学性能的影响规律,采用人工神经网络（artificial neural network, ANN）和遗传算法（genetic algorithm, GA）相结合的方法,构建了Al-Mg-Si系合金强度预测模型（ANN-GA模型）。通过单因素和双因素分析,研究了合金元素含量和热处理工艺参数对铝合金抗拉强度的影响规律。结果表明,随着Si含量的增加,铝合金的抗拉强度呈现先降低后升高的趋势;随着Mg含量的增加、Cu含量的增加或者Fe含量的减少,铝合金的抗拉强度整体上呈现升高的趋势。双因素分析更能反映输入参数对铝合金抗拉强度的影响。Mg/Si比、Mg+Si总量和时效时间对Al-Mg-Si系合金力学性能的影响显著。铝合金的硬度随时间的变化趋势与ANN-GA模型的计算结果一致,峰值时效时间为29 h,相对误差为11.86%。     

Si和RE对热浸铝镀层耐盐水腐蚀性能的影响

对铝浴中添加Ｓｉ和ＲＥ后批量热浸铝镀层的组织及耐盐水腐蚀性能的研究结果表明，铝浴中添加１￣７％Ｓｉ和适量ＲＥ，明显提高镀层耐腐蚀性能，减少镀层腐蚀速度随溶液温度升高而增加的幅度，但加入过量稀土则降低镀层耐蚀性，文中探讨了合金元素提高镀层耐蚀性能的原因。     

Microstructure and mechanical properties of extruded Mg-6.5Gd-1.3Nd-0.7Y-0.3Zn alloy

The Mg-6.5Gd-1.3Nd-0.7Y-0.3Zn alloy ingot and sheet were prepared by casting and hot extrusion techniques,and the microstructure,age hardening behavior and mechanical properties were investigated.The results show that the as-cast alloy mainly containsα-Mg solid solution and compounds of Mg5RE and Mg24RE5(RE=Gd,Y and Nd)phases.The grain size is refined after hot extrusion,and the Mg5RE and Mg24RE5 compounds are broken during the extrusion process.The extruded alloy exhibits remarkable age hardening response and excellent mechanical properties in the peak-aging state.The ultimate tensile strength,yield strength and elongation are 310 MPa,201 MPa and 5.8%at room temperature,and 173 MPa,133 MPa and 25.0%at 300℃,respectively.