Cu-Cr-La合金的热处理工艺研究

研究了固溶处理和时效处理工艺对Cu-0.3Cr-0.3La合金组织、硬度和电导率的影响.结果表明,Cu-0.3Cr-0.3La合金铸态组织粗大,950 ℃保温1 h固溶处理后,晶粒变得细小,富铬第二相明显减少,电导率和硬度较铸态都有所降低;经过950 ℃保温1 h固溶处理Cu-0.3Cr-0.3La合金,在400、450、500、550、600 ℃分别保温2 h时效处理后,硬度和电导率都有很大提高.在500 ℃保温2 h时效处理可获得良好的综合性能,其电导率和硬度分别可达96.3%IACS和99 HV.     

形变热处理对Cu-Ti-Fe-Sn合金组织与性能的影响

利用真空熔炼法制备了Cu-3Ti-0.2Fe-1Sn合金,通过均匀化退火、固溶+冷轧(变形量分别为40%、60%、80%)+450 ℃时效处理,研究了形变热处理对Cu-3Ti-0.2Fe-1Sn合金显微组织、导电率及硬度的影响。结果表明:真空熔炼制得的 Cu-3Ti-0.2Fe-1Sn合金铸态组织中含有大量的枝状晶组织,经固溶处理后组织中出现了晶粒长大;铸态合金的硬度和导电率分别为178.1 HV和10.85%IACS,固溶处理后硬度和导电率都相应降低,分别为102.7 HV和4.58%IACS。经过冷变形和时效处理后Cu-3Ti-0.2Fe-1Sn合金硬度明显提高,变形量为60%时,时效480 min时硬度达到峰值,合金硬度为310.2 HV,此时合金的导电率为18.59%IACS。     

热处理对Cu-Cr-Zr-Ni-Si-B合金组织与性能的影响

向Cu-Cr-Zr合金中添加Ni、Si、B元素制备Cu-Cr-Zr-Ni-Si-B合金,研究热处理对Cu-0.6Cr-0.15Zr-2.8Ni-0.7Si-0.06B合金显微组织、电导率和硬度的影响。结果表明：合金铸态组织为粗大的柱状晶,基体内部弥散分布着大量粗大过剩相;固溶处理后,过剩相基本溶解,晶粒明显长大;时效析出颗粒主要有Ni2Si、CrSi2、Cr3B4等化合物。随固溶温度的升高,合金硬度及电导率均快速下降,最低达到105.10 HV0.2、18.77%IACS。时效处理后,合金电导率、硬度都有大幅提升。经960 ℃×2 h固溶＋550 ℃×1 h时效后,硬度达到256.32 HV0.2,导电率达到39.7%IACS,软化温度达到575 ℃。     

热处理对Cu—Cr—Zr—La合金组织和性能的影响

研究了同溶时效处理对引线框架材料Cu-0.3Cr-0.1Zr-0.3La合金组织和性能的影响.采用光学显微镜分析了合金的组织.测试了不同工艺下合金的电导率和硬度.结果表明,Cu-0.3Cr-0.1Zr-0.3La合金铸态组织粗大,950℃×1h固溶处理后.晶粒变得细小,富铬第二相明显减少;在500、550、600和650℃分别保温2h时效处理后.组织明显细化,硬度和电导率都有很大提高;950℃×1 h同溶处理和550℃×2h时效处理,富Cr析出相变得细小、均匀分布在基体中.呈均匀的颗粒状,合金具有良好的综合性能,电导率和硬度分别达到97.1%IACS和87.2HV.     

固溶时效对Cu-4Ni-2Sn-Si合金组织及其性能的影响

采用OM、XRD、导电率和硬度测试等分析方法研究了固溶时效工艺对Cu-4Ni-2Sn-Si合金的显微组织及性能的影响。结果表明,热轧态Cu-4Ni-2Sn-Si合金中未溶解的第二相Ni2Si颗粒随着固溶温度的升高逐渐回溶,且发生再结晶,再结晶晶粒逐渐长大。当温度升高至900℃时,第二相粒子基本回溶到合金基体中。经时效处理后,合金的硬度受到析出相与再结晶的交互作用的影响。当时效温度低于450℃时,硬度值随时效时间的延长呈现先增大后减小的趋势;而时效温度升高至500℃时,合金硬度值随时效时间的延长而逐渐下降。而导电率则随时效时间的延长一直保持增大的趋势。热轧态Cu-4Ni-2Sn-Si合金经900℃×1 h固溶处理+68%冷轧变形+450℃×6 h时效处理后获得较优的综合性能,其硬度值为225 HB,导电率为24.5%IACS。     

微合金化Cu-Ni-Sn-P合金的组织和性能

利用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、显微维氏硬度计和涡流电导率仪,分析了不同镍锡比对Cu-Ni-Sn-P合金铸态、固溶态及时效态组织和性能的影响,从而优化了Cu-Ni-Sn-P合金中镍和锡元素的成分配比,同时研究了不同形变热处理工艺对Cu-0.87Ni-1.82Sn-0.07P合金组织和性能的影响。结果表明,Ni∶Sn为1∶2时Cu-Ni-Sn-P合金(Cu-0.87Ni-1.82Sn-0.07P合金)的综合性能最佳,固溶时效处理后硬度最高达119.9 HV0.5,电导率为35.0%IACS。时效前经过30%预冷轧变形能提高时效峰值硬度,450 ℃时效后硬度可达164 HV0.5。断口组织多为韧窝,韧性较好,抗软化温度为480 ℃。时效强化析出相与位错为切过关系,析出相呈现为球形Ni-P颗粒;晶界处析出颗粒较大,晶内析出的颗粒普遍较小,尺寸介于几十纳米到数百纳米之间。     

退火对窄热滞Ti-Ni-Cu-Cr形状记忆合金组织和拉伸性能的影响

在Ti-Ni合金中添加Cu、Cr得到热滞较小的Ti-45Ni-5Cu-0.3Cr形状记忆合金,用示差扫描量热仪、光学显微镜和拉伸实验研究退火温度(T_(an))对Ti-45Ni-5Cu-0.3Cr合金相变行为、显微组织和拉伸性能的影响。结果表明:350~700℃退火态Ti-45Ni-5Cu-0.3Cr合金冷却/加热时发生A→M/M→A(A-母相,Cs Cl型结构;M-马氏体,单斜结构)型相变,合金的相变热滞较窄;350~550℃退火态合金处于回复阶段,组织呈纤维状;600~700℃退火态合金处于晶粒长大阶段,组织呈等轴状;合金的再结晶温度在550~600℃之间;随退火温度升高,合金的马氏体再取向应力σ_M、抗拉强度和伸长率先升高后降低,400~500℃退火态合金的σ_M和抗拉强度最大,650℃退火态合金的塑性最好。     

Cu-10Ni-4.5Sn合金的铸态组织、性能及退火工艺

以Cu-10Ni-4.5Sn为研究对象,探讨合金的铸态组织、性能,以及均匀化处理及软化退火条件等对后续固溶时效处理强化效果的影响。试验研究表明,铸锭在冷轧开坯前,采用750℃×12h均匀化处理(均匀化处理后铸态合金的抗拉强度和电导率分别为241.3MPa和5.8MS/m),经过总加工率为60%的冷轧后,在700℃×6h条件下软化退火,再经总加工率为85%的冷轧,在800℃×1h固溶处理及400℃×6h下进行时效处理后,其带材的电导率及硬度(HV)可达8.8MS/m和378.6,合金抗拉强度及伸长率分别为1275.9MPa和3.0%。     

微量Mg元素对Cu-15Ni-8Sn合金组织及性能的影响

通过对不同Mg含量的Cu-15Ni-8Sn合金铸态、固溶态和时效态的微观组织进行分析,研究了微量Mg对Cu-15Ni-8Sn合金组织及性能的影响。结果表明,添加的Mg元素会在富Sn相中偏聚,并且可以显著抑制时效过程中不连续沉淀相的析出,从而改善合金的力学性能。此外,随着Mg添加量增加,合金的峰值时效硬度增大,电导率降低。在Mg含量为0.3%时,合金的硬度(HV)和电导率分别为369和4.85 MS/m,相较未加入Mg时硬度(HV)提高了11,电导率下降了0.26 MS/m。     

Cu-4Ni-2Sn-Si合金的铸态组织及均匀化退火工艺的研究

采用OM、SEM、EDS及硬度测试等分析方法研究了Cu-4Ni-2Sn-Si合金的铸态显微组织,以及均匀化退火对合金显微组织及性能的影响。结果表明,铸态Cu-4Ni-2Sn-Si合金的显微组织枝晶发达,合金元素分布不均匀,Sn呈反偏析现象,且室温组织由α-Cu和δ-Ni2Si相组成。随着均匀化退火温度的升高及保温时间的延长,合金元素的分布趋于均匀化,Sn的反偏析现象基本被消除,有大量δ-Ni2Si析出且趋于均匀化分布,均匀化退火效果受温度影响较大。由此建议Cu-4Ni-2Sn-Si合金较佳的均匀化退火条件为850℃×4 h,其硬度值为HB99.5,电导率为16.64%IACS。     

退火处理对超细晶Cu-Cr合金组织和性能的影响

对Cu-0．4Cr合金进行ECAP（等通道转角挤压）8道次的挤压，得到晶粒尺寸为500nm的等轴晶组织，然后在电阻炉内进行退火试验，通过对ECAP细晶的铜铬合金在473～873K退火1h，分析合金的组织和性能，研究该合金的硬度和导电性能。研究发现，弥散的Cr可以有效地阻止合金的晶粒长大；723K退火后，Cu-0．4Cr合金的电导率和硬度分别可达80．3％IACS和210．9HV，并有较好的综合性能。     

FeCoCrNiMn高熵合金大形变冷轧板再结晶退火过程中的组织演变

采用X射线衍射仪(XRD)、维氏硬度计、光学显微镜和电子背散射衍射(EBSD)研究了FeCoCrNiMn高熵合金经压下率为95%的大形变冷轧和550~800 ℃退火1 h后的晶体结构(fcc)、硬度变化、组织演变和再结晶行为。结果表明,冷轧-退火过程中FeCoCrNiMn高熵合金的晶体结构始终保持面心立方结构,再结晶开始温度为600 ℃,结束温度为750 ℃,随着退火温度的升高,试样的硬度先下降后逐渐趋于平缓,组织由纤维状的形变晶粒逐渐全部变为随机取向的再结晶晶粒。     

Cu-Cr-Fe-Ni合金形变热处理过程中的组织与性能

采用非真空熔炼并经热轧—固溶—冷轧—时效热处理工艺制备Cu-0.59Cr-0.078Fe-0.081Ni合金板,探究热处理和冷变形对合金显微组织、电导率和硬度的影响。结果表明:Cu-Cr-Fe-Ni合金大气熔铸后呈明显的枝状晶组织,经固溶处理后合金发生再结晶,硬度和电导率都相应的降低,分别为65.9 HV0.2、41.7%IACS;经过冷变形处理后合金的硬度显著提高,变形量达90%时,合金的硬度高达144.7 HV0.2;合金变形后在450 ℃时效的过程中硬度先增加后减少,变形量为60%时,时效30 min达到峰时效,此时硬度、电导率分别为155.5 HV0.2、71.4 %IACS。     

Zr-Sn-Nb-Fe锆合金板材轧制及热处理过程中的晶粒组织演变

采用光学显微镜(OM)和扫描电镜(SEM)分析研究了Zr-Sn-Nb-Fe锆合金板材在热轧及退火→中间冷轧及退火→成品轧制及退火的全工艺流程中晶粒组织的演变规律。结果表明,热轧后合金组织沿轧制方向呈带状分布,晶粒粗大并破碎变形;中间冷轧和成品轧制后合金为沿轧制方向带状分布的细小形变组织,合金组织明显细化;中间退火和成品退火后合金中晶粒再结晶程度较热轧退火时明显提高,晶粒取向差逐渐向正态分布变化,晶粒组织也逐渐均匀化和细化,最终获得细小、均匀分布的完全再结晶晶粒组织,晶粒度12级。     

Influence of Fe addition on microstructure and properties of Cu-Ag composite

We investigated the effects of Fe content on microstructure and properties in as-cast and as-drawn Cu-(5.1-x) vol%Ag-x vol%Fe alloys. In microscale, increasing Fe content first refined and then coarsened Cu dendrites. In nanoscale, the size and length of Ag precipitates in Fe-doped alloys were smaller than the size and length of Ag precipitates in Fe-free alloy, and the γ-Fe precipitates in Cu-2.9 vol%Ag-2.4 vol%Fe alloy were finer than the γ-Fe precipitates in Cu-5.1 vol%Fe alloy. The maximum hardness in as-cast Cu-Ag-Fe alloys was found in the Cu-2.9 vol%Ag-2.4 vol%Fe alloy. With increasing drawing strain, both ultimate tensile strength and hardness of Cu-Ag-Fe composites were increased. Simulation data among the relative volume fractions of Fe, hardness and electrical conductivity showed that, as the relative value approached 40%, the Cu-Ag-Fe composite displayed greater hardness than other samples. As a small amount of Ag was replaced by Fe, the electrical conductivity decreased significantly with a descending slope of approximately 3%IACS (International Annealed Copper Standard) per vol% Fe. As 47 vol%Ag was replaced by Fe, however, the electrical conductivity decreased by 51% and remained almost invariable with further increasing Fe content. After annealing at 450 °C for 4 h, the electrical conductivity of the Cu-2.9 vol%Ag-2.4 vol%Fe composite was elevated up to 68.3%IACS from 38.5%IACS.     

Microstructures and properties of cold drawn and annealed submicron crystalline Cu-5%Cr alloy

The microstructures and properties after cold drawing and subsequent annealing of submicron crystalline Cu-5%Cr (mass fraction) alloy were investigated. The results show that, the microstructure of submicron crystalline Cu-5%Cr can be further refined by cold drawing. After cold drawing, the grains of Cu-5%Cr alloy with grain size of 400-500 nm can be refined to be cellular structures and subgrains with size of 100-200 nm. Both strength and ductility of Cu-5%Cr alloy can be enhanced by cold drawing, and the optimal mechanical properties can be achieved with drawing deformation increasing. It is suggested that dislocation glide is still the main mechanism in plastic deformation of submicron crystalline Cu-5%Cr, but grain boundary slide and diffusion may play more and more important roles with drawing deformation increasing. When the cold drawn Cu-5%Cr wires are annealed at 550 ℃, fine recrystal grains with grain size of 200-300 nm can be obtained. Furthermore, there are lots of fine Cr particles precipitated during annealing, by which the recrystallization softening temperatures of the cold drawn Cu-5%Cr wires can be increased to 480-560 ℃. Due to the fact that Cr particles have the effect of restricting Cu grains growth, a favorable structural thermal stability of the submicron crystalline Cu-5%Cr can be achieved, and the submicron grained microstructure can be retained at high temperature annealing.     

Effect of V addition on hardness and electrical conductivity in Cu-Ni-Si alloys

The effect of vanadium (V) addition on the microstructure, the hardness and the electrical conductivity of Cu-2.8Ni-0.7Si alloys was investigated. The V-free, the 0.1 wt% V-added, the 0.2 wt% V-added Cu base alloys were exposed to the same experimental conditions. After the cold rolling of the studied alloys, the matrix was recrystallized during the solution heat treatment at 950 °C for 2 h. However, small amounts of vanadium substantially suppressed the recrystallization and retarded the grain growth of the Cu base alloys. The added vanadium accelerated the precipitation of Ni₂Si intermetallic compounds during aging and therefore it contributed positively to the resultant hardness and electrical conductivity. It was found that the hardness and the electrical conductivity increased simultaneously with increasing aging temperature and time with accelerated precipitation kinetics by the addition of vanadium. In the present study, the Cu-2.8Ni-0.7Si alloy with 0.1 wt%V was found to have an excellent combination of the hardness and the electrical conductivity when it was aged at 500 °C.     

Cu-9.5Ni-2.3Sn-0.5Si合金的固溶处理工艺与组织性能研究

采用金相显微镜、扫描电镜、EDAX能谱仪、X射线衍射仪、SIGMASCOPE SMP10型导电仪、维氏硬度计等,研究了热处理工艺对Cu-9.5Ni-2.3Sn-0.5Si合金组织和性能的影响。结果表明:Cu-9.5Ni-2.3Sn-0.5Si合金晶粒尺寸随固溶温度升高而长大;随着固溶温度的升高或固溶时间的延长,电导率先降后升,而硬度则下降。此外,合金经850℃×2 h固溶处理后,形成了Ni2Si、Ni31Si12相并占据了γ-(Cu,Ni)3Sn相的形核位置,此时电导率为12.0%IACS,硬度可达152 HV。