合金薄膜铜衬底抛光质量对薄膜表面结构的影响

合金薄膜具有良好的导电性、抗磨损性质,已成为半导体产业的技术热点.铜做为合金薄膜衬底材料时,要求其有完美的表面.本文采用氧化铝微粉和金刚石抛光膏对合金薄膜铜衬底进行了机械研磨和抛光的实验研究,采用接触式粗糙度仪、AFM、台阶仪和光学显微镜对比分析了铜衬底表面粗糙度、表面均匀性和平面度的变化规律.初步探讨了铜衬底表面对Pd-Ni-P合金薄膜表面结构的影响,研究结果表明采用1 μm平面度,Ra小于3 nm且抛光均匀性好的光滑铜衬底可以获得良好的合金薄膜.     

沉积温度对ZnO薄膜结构及发光性能的影响

利用Nd-YAG激光器(波长为1064nm,频率为10Hz)做光源,采用纯金属锌靶,以Si(111)为基体在有氧的气氛中通过激光烧蚀锌靶表面来制备氧化锌薄膜,研究基体温度对ZnO薄膜结构及发光性能的影响.通过XRD和AFM原子力显微镜来表征氧化锌薄膜的结构和表面形貌,其光学性质由光致发光谱来表征.结果表明:在450-550 ℃的条件下沉积的ZnO薄膜具有c-轴择优取向,500℃时c-轴取向最明显.具有c-轴取向的ZnO薄膜具有强的紫外光发射和弱的绿光发射,发光中心在518nm处的黄绿光发射主要归因于电子从导带底部到氧位错缺陷OZn能级之间的跃迁.     

脉冲电镀Ni-Co合金在高温处理下的结合力变化

采用数控双脉冲电源电镀钢基Ni-Co合金,并分别研究了热处理温度、热处理时间、基体预处理对镀层结合力的影响。实验结果表明:Ni-Co合金镀层在不同温度下热处理1h,其结合强度随着热处理温度增加而减小,且减小的幅度逐渐变小。温度达到400℃后,结合强度平稳增加;Ni-Co合金镀层在400℃下热处理,其镀层结合强度在前30min内缓慢增加,最大达5.41MPa,随后大幅下降至一个相对较低的水平上。经过预处理的基体力学性能得到改善,塑性变形区增大,屈服强度增加,增强了镀层的结合强度。     

熔体温度处理工艺对A319合金组织和性能的影响

研究了熔体温度处理工艺对A319合金凝固组织的影响,通过对冷却速度和混合熔体停留时间的考察,发现不同的冷却速度对经过和不经过熔体温度处理的凝固组织初生枝晶尺寸作用不大,但对凝固组织中的晶间化合物相的析出有很大影响。研究结果表明,熔体温度处理工艺有利于抑制晶间化合物的析出,促进组织的均匀性,随着混合熔体停留时间的延长,试样的拉伸性能表现出由低到高,再由高到低的变化规律,从原子团族的角度分析了熔体温度处理工艺对凝固组织的作用机制。     

基板温度对电热爆炸喷涂制备粘结层性能的影响

基板温度分别为室温、100和200 ℃时,采用电热爆炸喷涂技术在IC10合金表面制备NiCoCrAlY合金粘结层.利用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD),对热循环前后的粘结层的组织形貌、化学成分及相进行分析.结果表明,基板温度对电热爆炸喷涂技术所制备NiCoCrAlY合金粘结层有明显的影响,随着基板温度的升高,所制备的粘结层与基体界面结合良好,表面粗糙度减小.在1050 ℃热循环后粘结层表面生成了Al2O3氧化层,起到了保护基体的作用.     

扩散温度对TC4合金表面Cu/Ni复合镀层结构及腐蚀性能的影响

论文采用扩散热处理研究了Cu/Ni/Ti复合镀层不同温度下的扩散行为,分析了扩散层结构,并讨论了扩散过程对镀层结构及腐蚀性能的影响。结果表明：由于Cu/Ni/Ti原子之间的互扩散,形成稳定的扩散层,可以有效提高镀层表面耐蚀性能;随着热扩散温度上升到700℃,膜层结构致密,在扩散层中形成了NixTiy金属间化合物及少量的CuxTiy金属间化合物,镀层表面的耐蚀性最好;温度升高到800℃时,在膜层界面处引发了Kirkendall效应,所形成的Kirkendall空位相互聚集长大,形成裂纹或孔洞,使得镀层疏松多孔,从而低了耐蚀性。     

Ti-Mo合金的缺陷结构对材料性能的影响

采用真空烧结方法,分别在870℃、890℃制备Ti-Mo（9：1）多孔合金,对材料的微观结构及吸气性能进行研究。结果表明,高温样品中存在大量的α/β界面和β1/β2界面,α/β界面附近存在大量各种类型的缺陷。结合吸气性能测试结果,表明α/β界面及其附近的大量缺陷有利于提高Ti-Mo样品的吸气性能。     

2A12铝合金精密件基体表面粗糙度对低温磁控溅射TiN的影响

研究2A12铝合金精密件表面在低温磁控溅射沉积TiN薄膜过程中,基体表面粗糙度对成膜过程及薄膜显微硬度的影响。结果表明,低温磁控溅射沉积处理几乎不改变2A12铝合金精密件基体原始表面形貌,对其精密加工状态具有遗传性或复制性。通过显微硬度测试表明,随着2A12铝合金精密件加工精度的提高,基体表面粗糙度降低,TiN薄膜的显微硬度稳定在19 MPa以上,满足了2A12铝合金精密测试杆特殊功用的要求。     

Effect of low temperature melt on solidification structure of A356 alloy with melt thermal treatment

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Effect of substrate temperature on the splat formation of flame sprayed polypropylene

Polypropylene (PP) powder particles were thermally sprayed via a flame spray onto mild steel substrates at room temperature (RT), 70 °C , 120 °C, and 170 °C. Single solidified splats were collected from polished substrates. The splat morphology was characterized using optical microscopy and scanning electron microscopy (SEM). Micro-Raman spectroscopy examined the effect of substrate preheating on the molecular structure of the PP splats. The splat-substrate interface, porosity and a qualitative interpretation of the interface adhesion were obtained by cross-sectioning and imaging using the focused ion beam (FIB) technique.This study indicated that increasing the substrate temperature from room temperature to 170 °C produces PP splats of larger diameter that would be expected to exhibit improved adhesion. The influence of preheating dominates the splat formation and splat morphology. The Raman spectra indicate that the degree of crystallinity of the PP particles rises with increasing substrate temperature. Comparison of the spectra of the feedstock and the deposited PP particles confirms that there is no thermal degradation of the material under these processing conditions.This work demonstrates the influence of substrate chemistry on the PP splat morphology. Microstructural characteristics are related to the flame spray process variables for polymeric coatings.     

Effect of sintering temperature on the room temperature properties of Al90Mn8Ce2 alloy

Using a powder hot-pressing technique, a high-strength Al-8Mn-2Ce alloy (atomic percent (at.%)) in a size of φ20 × 10 mm has been made. The parameters used to obtain the highest strength of 895 MPa for the alloys are a pressing temperature of 803 K, a pressing time of 15 min, and a pressing stress of 1.2 GPa.     

Effect of gadolinium on aged hardening behavior,microstructure and mechanical properties of Mg-Nd-Zn-Zr alloy

Mg-3.4Nd-0.1 Zn-0.40Zr alloy samples with and without containing gadolinium(0.6%,mass fraction)were prepared by sand casting.The aged hardening behavior,solidification microstructures and mechanical properties of the alloys were investigated by using the analysis methods of OM,XRD,TEM,hardness tests and mechanical property tests.The main research results are as follows.1)Compared with the alloy without the addition of gadolinium.the alloys with the addition of gadolinium shows the more remarkable age-hardening response.2) The as-cast microstructure of the alloy with and without containing gadolinium consists of α-Mg grains with Mg12Nd phase on the grain boundary.After solution heat-treatment,Mg12Nd phase of the alloy without containing gadolinium is dissolved in the matrix,however,there iS still discontinued Mg12Nd phase at grain boundary of the alloy with containing gadolinium.The more finely dispersed precipitates in Mg matrix are formed in the alloy with containing gadolinium during age-treatment.3)The room temperature and high temperature mechanical properties ofthe alloy are satisfactory.with σb=280 MPa,σ0.2=165 MPa at RT and aσb=215 MPa,σ0.2=155 MPa at 250℃.The high temperature mechanical properties decrease slightly with the increase of temperature.     

Effect of substrate temperature on adhesion strength of plasma-sprayed nickel coatings

We plasma-sprayed nickel coatings on stainless steel and cobalt alloy coupons heated to temperatures ranging from room temperature to 650 °C. Temperatures, velocities, and sizes of spray particles were recorded while in-flight and held constant during experiments. We measured coating adhesion strength and porosity, photographed coating microstructure, and determined thickness and composition of surface oxide layers on heated substrates. Coating adhesion strength on stainless steel coupons increased from 10–74 MPa when substrate temperatures were raised from 25–650 °C. Coating porosity was lower on high-temperature surfaces. Surface oxide layers grew thicker when substrates were heated, but oxidation alone could not account for the increase in coating adhesion strength. When a coupon was heated to 650 °C and allowed to cool before plasma-spraying, its coating adhesion strength was much less than that of a coating deposited on a surface maintained at 650 °C. Cobalt alloy coupons, which oxidize much less than stainless steel when heated, also showed improved coating adhesion when heated. Heating the substrate removes surface moisture and other volatile contaminants, delays solidification of droplets so that they can better penetrate surface cavities, and promotes diffusion between the coating and substrate. All of these mechanisms enhance coating adhesion.     

冷轧预变形量对1460合金组织和性能的影响

本文研究了时效前不同冷轧预变形量（ε=7%,14%,20%,27%）对1460合金沉淀强化过程的影响。当冷轧变形量增加至20%时,合金中出现位错墙（Dense Dislocation Wall）。位错为T1相提供了形核位置,使得合金中T1相的数量增加同时尺寸保持在100 nm 左右,缩短了时效峰值时间。27%冷轧变形+160 ℃/12 h时效能提高合金的强度,同时塑性较好,此时合金的抗拉强度和延伸率分别为590 MPa和8%。     

Effect of high density pulse electric current on solidification structure of low temperature melt of A356 alloy

The effect of high density pulse electric current(HDPEC)on the solidification structure of the low temperature melt(LTM)of commercial A356 alloy was investigated.In th experiments.the HDPEC was discharged in the LTM(953K,903K and 873K),By the control experiments,the results showed that the solidification structure of the LTM of A356 alloy is refined apparently when the HDPEC is discharged in low temperature melt.However,the holding time of melt treated has an adverse effect on the soliification structure.The longer the holding time of the melt treated with HDPEC,the coarser the microstructure.With the same discharge voltage.the lower the temperature of LTM,the more obscure the refinement of solidification structure.Finally,the mechanism of microstructure refining by HDPEC was analyzed.     

深冷处理和温度对Fe-Mn合金阻尼性能的影响

通过测定Fe-Mn合金的层错几率以及借助G-L位错脱钉模型,研究了深冷处理和温度对其阻尼性能的影响,进一步揭示了Fe-Mn合金的高阻尼机制.采用倒扭摆测试合金的阻尼性能、SEM观察显微组织、XRD测定物相体积分数和层错几率.结果表明,Fe-Mn合金的高阻尼机制与Shockley不全位错的脱钉运动相关;深冷处理增加了合金的层错几率,即增加了Shockley不全位错数量,阻尼性能得到提高;升高温度降低了Shockley不全位错的脱钉力,在一定应变振幅下,温度越高可以产生脱钉的Shockley不全位错数量就越多,合金的阻尼性能升高.     

高温热处理对Nb-Ti-Cr-Si基超高温合金显微组织的影响

为了研究高温均匀化及时效热处理对Nb-Ti-Cr-Si基超高温合金显微组织的影响,对样品进行均匀化处理,于1200-1500°C保温24h,随后于1000°C保温24h进行时效。结果表明,热处理后的组织主要由Nbss、（Nb,X）5Si3和Cr2Nb组成。随着均匀化处理温度的升高,电弧熔炼态的树枝状Nbss转变为等轴状,原先花瓣状的Nbss/（Nb,X）5Si3共晶组织消失,转变为分布于Nbss基体上的小块状（Nb,X）5Si3组织。Cr2Nb的形貌随均匀化处理温度的升高而发生明显变化。当均匀化处理温度达到1300°C以上,原先粗大的Cr2Nb发生溶解,在随后的冷却过程中在Nbss基体上沉淀析出细小、密集的针状Cr2Nb。经高温均匀化和时效复合处理后,Nbss基体上析出更为细小、密集的沉淀相Cr2Nb,使得Nbss、（Nb,X）5Si3和Cr2Nb相中Ti、Hf和Al元素的含量差别缩小。     

熔体温度处理对不同成分铝合金凝固组织和性能的影响

运用熔体温度处理工艺 ,研究了A35 6铝合金中Cu ,Fe ,Mg成分的变化对凝固组织及性能的影响。组织观察和性能测试结果表明 ,熔体温度处理工艺能够明显抑制富Cu、富Mg、富Fe等金属间化合物相的析出 ,改善和减小了富Cu、富Mg、富Fe相析出形貌和尺寸 ,显著地提高合金力学性能。用团簇理论分析和解释了有关的实验现象和结果。     

温度对AZ80镁合金高温拉伸变形行为的影响

通过高温拉伸试验,研究了AZ80镁合金在300~450 ℃、变形速率1 mm/min条件下的高温变形行为。结果表明,在不同温度条件下,AZ80镁合金的高温拉伸应力-应变曲线均出现峰值,峰值应力随变形温度的升高而减小,而塑性随着变形温度的升高,先升高后降低。结合微观组织和断口形貌可以得出,AZ80镁合金在425 ℃下具有最好的变形能力。