海外文献速报

正20151201 SAINI N,DWIVEDI D K,JAIN P K,et al.搅拌摩擦加工制备铸造Al-17Si合金的表面改性研究.Procedia Engineering,2015,100:1 522-1 531.Al-Si合金常用于生产发动机零件,如连杆、活塞、外壳等。该类材料在防护、汽车、航空航天领域具有较大的需求。然而,传统方法铸造所得Al-Si合金容易产生气孔、缩松、初生Si的偏     

油气田CO2腐蚀的防护技术研究

本文论述了油气开采过程中的CO2腐蚀的防护技术。CO2腐蚀的防护技术主要包括：抗CO2腐蚀材料技术、材料表面处理技术、阴极保护技术和注缓蚀剂技术。针对目前CO2腐蚀的防护技术方面存在的不足,提出了建议。     

硫脲在不同晶化程度的FeNiSiB非晶合金表面的缓蚀行为

本文采用动电位扫描及电化学阻抗测量技术研究硫脲(TU)在不同晶化程度的非晶合金上的缓蚀行为,实验表明,TU在不同晶化程度的非晶合金表面上的缓蚀行为及缓蚀能力不同。非晶合金与吸附型缓蚀剂的吸附作用低于部分晶化合金,添加吸附型缓蚀剂不是非晶合金理想的防护措施。     

TiAl合金高温抗氧化表面防护技术

TiAl合金作为重要的高温结构材料,其高温抗氧化性能有待改善。表面防护技术是提高TiAl合金高温抗氧化性能的有效方法。本文综述了TiAl合金高温抗氧化表面防护技术的研究进展,阐述了表面合金化层及表面防护涂层的机理和特性,总结了防护技术的应用和存在的不足,并对TiAl合金抗高温氧化表面防护技术研究的发展趋势进行了展望。     

海外文献速报

正20151201 SAINI N,DWIVEDI D K,JAIN P K,et al.搅拌摩擦加工制备铸造Al-17Si合金的表面改性研究.Procedia Engineering,2015,100:1 522-1 531.Al-Si合金常用于生产发动机零件,如连杆、活塞、外壳等。该类材料在防护、汽车、航空航天领域具有较大的需求。然而,     

Al-Si系合金表面氩弧强化及其灰关联分析

在Al-Si系合金表面熔入Fe,Mn,Ni,Re等合金元素，以提高Al-Si系合金表面硬度，提高其耐磨性能，并利用灰色系统理论知识对试验结果进行了分析。     

汽车用镁合金激光表面熔覆Al-Si合金涂层组织和性能研究

采用激光熔覆技术在汽车用镁合金表面制备Al-Si合金涂层,对Al-Si合金涂层的组织和性能进行研究。结果表明,Al-Si合金熔覆层组织主要为树枝晶,主要物相为Mg_2Al_3、Mg_(17)Al_(12)、Mg_2Si。镁合金激光表面熔覆Al-Si合金涂层硬度分为4个不同区域,分别为熔覆层、结合区、热影响区和镁基体,其中次表层硬度最高,基体层硬度最低。镁合金表面随着激光功率的增加,熔覆层耐磨性和耐腐蚀性能提高。随着激光功率的增加,耐磨性先增加后降低,耐蚀性逐渐提高。     

等离子喷涂YSZ/NiCrAlY涂层及抗熔融Al-Si腐蚀性能研究

热浸镀Al-Si合金涂层是一种高效的耐蚀技术。然而,其生产过程中与Al-Si熔液直接接触的部件存在严重的Al-Si熔蚀问题。采用大气等离子喷涂(APS)制备了YSZ/NiCrAlY涂层,研究了主气流量对YSZ(Y-Si-Zr)涂层微观组织结构、力学性能的影响规律、涂层的高温稳定性和耐Al-Si熔液腐蚀行为。结果表明,随着主气流量的提升,粒子熔滴的铺展均匀性、涂层致密度、力学性能均先升高后降低。在主气流量(Ar)为40L/min时,涂层显示出最佳的表面平整度、最大的致密度以及最优的力学性能。在1000℃热处理100 h后YSZ涂层的界面结构稳定,孔隙率下降,致密度显著提高。此外,将试样在700℃熔融Al-Si液腐蚀50h后,在YSZ涂层与熔融Al-Si合金的界面没有发现互反应区和元素互扩散现象,并且Al-Si熔液没有渗透进涂层内部而是被阻挡在涂层表面,表明APS制备YSZ/NiCrAlY涂层能够有效地抵抗Al-Si熔液腐蚀,可作为与高温Al-Si熔液接触部件的最有潜力的防护涂层之一。     

具有超疏水表面的铜及铜合金耐蚀行为研究进展

随着铜及其合金的广泛应用,腐蚀问题也造成了巨大的社会和经济损失,超疏水表面处理是一种新型且非常有前景的金属防腐蚀方法。本文简要介绍了用于制备铜基超疏水表面的疏水材料和方法;重点分析了超疏水表面对铜及铜合金耐蚀性能的影响;归纳了超疏水表面防腐蚀的机理;总结了超疏水表面防腐蚀的技术障碍;最后提出了超疏水表面与缓蚀剂联合防腐蚀的新思路。     

包埋渗结合激光熔覆制备复合涂层的高温抗氧化性

为了提高铌合金的抗氧化性能,采用铝硅共渗的方法在铌合金表面制备Al-Si涂层,结合激光熔覆技术于渗层上熔覆MOSi2涂层。探讨了Al-Si渗层的生长机制,研究了铌合金表面Al-Si渗层及MoSi2/Al-Si涂层的抗高温氧化性能。结果表明:Al-Si渗层的形成过程是源于Al、Si元素的先后沉积,优先形成了Al3Nb相。渗层厚度x与保温时间f遵循关系式:x=At1/2+7.4(1000℃:A=11.6,1050℃:A=16.2)。激光熔覆制备的MoSi2/Al-Si涂层均匀连续致密,与基体结合紧密,无裂纹孔洞等缺陷。主要相结构为MoSi2、Al3Nb、NbSi2、Nb5Si3和Mo(Si,Al)2。经1200℃氧化后,Al-Si渗层及MoSi2/Al-Si涂层都形成大量的SiO2保护膜,阻止了氧原子的进一步扩散。与Al-Si渗层相比,MoSi2层表面形成的连续致密混合氧化物有效避免了Al-Si渗层的快速消耗,MoSi2/Al-Si涂层的高温氧化优于Al-Si渗层。     

选区激光熔化Al-Si合金组织特征及腐蚀行为研究进展

选区激光熔化(selective laser melting, SLM)制备的Al-Si合金在航空航天材料定制化和轻量化的发展中有着巨大潜力。然而,影响SLM成形件寿命的腐蚀行为尚未引起广泛关注。本文结合当前文献报道,根据SLM过程中的凝固特征分析了冶金缺陷和微观组织的形成原因,结合传统铸造Al-Si合金在含氯化合物中的腐蚀机理,进一步论述了SLM制备的Al-Si合金的腐蚀机理,归纳总结了冶金缺陷、微观组织和热处理工艺对于腐蚀行为的影响。发现试样的致密度,表面状态(粗糙度)和共晶Si的含量、形态及分布对腐蚀性能有重要影响。在此基础上,指出了目前SLM工艺下Al-Si合金腐蚀研究中存在的工艺参数不够系统,忽视Mg,Fe等元素的作用,研究手段和范围不够完善等不足以及未来进一步发展的方向。     

Application of ceramic short fiber reinforced Al alloy matrix composite on piston for internal combustion engines

The preparation and properties of ceramic short fiber reinforced Al-Si alloy matrix composite and it's application on the piston for internal combustion engines are presented.Alumina or aluminosilicate fibers reinforced Al-Si alloy matrix composite has more excellent synthetical properties at elevated temperature than the matrix alloys.A partially reinforced Al-Si alloy matrix composite piston produced by squeeze casting technique has a firm interface between reinforced and unreinforced areas,low reject rate and good technical tolerance.As a new kind of piston material,it has been used for mass production of about 400,000 pieces of automobile engines piston.China has become one of a few countries in which aluminum alloy matrix composite materials have been used in automobile industry and attained industrialization.     

Corrosion performance and mechanical properties of joined automotive materials

The automotive industry envisions that an optimized vehicle in terms of performance and cost can be achieved only by using different materials at different vehicle locations in order to utilize the functionality of the different materials to a full extent. Currently, steel and aluminum are the most important construction materials for the mass production of automotive structure. However, other materials such as magnesium alloys and stainless steel are also used. The use of dissymmetric assemblies of materials in the automotive industry has also led to the development of joining technologies other than spot welding and arc welding such as clinching, adhesive bonding, laser welding, and MIG brazing. However, and despite the development of these new joining technologies, there are still important gaps of knowledge with regards to the corrosion performance of different joint populations using dissymmetric and symmetric materials. Materials commonly used in the automotive industry including steel and aluminum‐based susbtrates were assembled with different combinations using various joining techniques in order to evaluate their corrosion performance as well their mechanical properties after cyclic accelerated corrosion tests. The results indicated a relationship between the corrosion inside the confined joint and the decrease of the mechanical properties of the assemblies.     

金属表面腐蚀层及涂层的激光干式清洗研究进展

激光干式清洗方法,因操作简单、清洗过程易于控制等优点,目前应用最为广泛。重点介绍了激光干式清洗在各种金属材质表面不同腐蚀层和涂层清除中的应用,包括有多种钢材表面的锈层,钢材表面的ZrO2、Cr2O3、Al2O3变性层,热轧钢表面高温氧化层,Ti合金表面富氧α相层,合金钢在H2S环境中腐蚀而形成的硫化层,钢、铝合金、钛合金表面漆层,热压成型钢板表面Al-Si涂层以及航空压缩机Ti合金叶片TiAlN涂层等。分类对比了不同清洗对象所需选用的合适激光清洗工艺参数,如波长、脉宽、频率、功率、扫描速率等。金属材料激光干式清洗多选用波长为1064 nm的纳秒激光器,清洗后表面粗糙度可达1μm,且随着能量输入的升高而增大。锈层的去除主要依靠高温烧蚀作用,变性层是由于产生的热弹性应力而剥离,而漆层和涂层则是由于烧蚀气化、热振动、热冲击等机制实现清洗。最后,对激光清洗技术在国内不同工业领域中的应用前景进行了展望。     

Filiform corrosion attack on pretreated aluminum alloy with tailored surface of epoxy coating

In the study, on the basis of material analysis of 6016 aluminum alloy widely used in Europe automotive industry, the influences of surface pretreatment on filiform corrosion and adhesion of epoxy coating/aluminum alloy interface were investigated, and the effect of rolling direction and coating property on filiform corrosion was also examined. The alloy surfaces were pretreated with etching solution, and then, respectively, with Aminopropyl silane solution, Aminopropyl phosphonate solution, and hexamethyldisiloxane plasma.The results showed that the susceptibility of pretreated surface to filiform corrosion was basically consistent with the distribution of intermetallic particles, and that water permeation and the tensility of coating were necessary for filament to grow. HMDSO plasma pretreatment could not only efficiently cover the matrix of 6016 aluminum alloy and cathodic intermetallic particles containing Al, Si, Mn, and Fe, but also apparently promote the adhesion of epoxy coating/aluminum alloy, as a result, the specimens with plasma pretreatment exhibited the superior performance in the filiform corrosion and peeling tests, so it was suitable to apply for the pretreatment of aluminum alloy in automotive industry.     

Hochlegierte korrosionsbeständige Stähle für Chemie‐, Energie‐ und Meerestechnik – Rückblick und Ausblick

High‐alloyed corrosion resistant steels for the chemical process industry, power engineering and marine technology – past and future Today's most common high‐alloyed corrosion resistant steels are in their majority characterised by very low contents of carbon and sulphur and, in many cases, by substantial amounts of nitrogen as an alloying constituent. Their broad use in the chemical process industry, power generation and marine technology has become possible when new metallurgical processes for steel making had been introduced in the 1960s. The time before had seen mainly stabilised grades, being highly alloyed with copper in many cases, which have disappeared to a large extent in our days. The superferritic grades (ferritic steels with ≥ 25% chromium) had been the materials of great expectations in the 1970s, but have found a very limited application only in the chemical industry since then, e.g. for the handling of hot concentrated sulphuric acid, due to the high risks of low ductility cracking of these materials at greater wall thickness. These risks can be managed better if the highly alloyed ferritic phase is present in a finely dispersed compound with an austenitic phase where the ferritic part is adding its advantages, higher strength and resistance to stress corrosion cracking, to the duplex compound. This can result in low weight and corresponding cost saving. The application of the corrosion resistant duplex grades will expand further as much as users will better learn the special requirements of manufacturing of these materials and to take advantage of their unique properties. However, the most important alloy developments since the 1960s have been seen in the field of the austenitic stainless steels being highly alloyed with chromium, molybdenum and nitrogen. Especially the austenitic 6% Mo grades as e.g. X1NiCrMoCuN25‐20‐7 – alloy 926 (1.4529) have found many applications in chemical process industry, power generation and marine technology. Higher alloyed grades as e.g. X1NiCrMoCu32‐28‐7 – alloy 31 (1.4562) are excelling in extraordinary resistance to corrosion by acids and pitting attack. In addition today's upper limits of alloying austenitic corrosion resistant grades have been explored with grade X1CrNiMoCu33‐32‐1 – alloy 33 (1.4591) for chromium additions up to about 33% and with grade X1NiCrSi24‐9‐7 – alloy 700 Si (1.4390) for additions of silicon up to about 7%, providing a high corrosion resistance mainly in oxidising acids. When considering the prospects of further development of the corrosion resistant duplex grades the ferritic phase within these materials is both offering chances and setting limits. The high‐alloyed austenitic corrosion resistant steels have a potential being unexplored so far in the alloy range where molybdenum and nitrogen are becoming more prominent compared to the chromium content.     

镁合金表面改性技术研究现状及进展

镁合金有高的比强度,使其成为汽车、航空等工业今后减重的选用材料;它有良好的抗电磁信号干扰、吸震（阻尼）性能和环境友好性等,使其在电子工业领域应用潜力巨大。但镁合金缺乏自医的、自然钝化的表面膜,使其在使用过程中易腐蚀,尤其在潮湿空气、海水、各种有机酸及其盐、无机酸等环境中其耐蚀性差。目前,在镁合金表面改性方面采用的方法不外乎表面涂层技术,以保护镁合金基体不与外部环境接触。本文结合作者在镁合金表面扩渗合金化方面所做的研究工作以及金属镀层、阳极氧化法和高能束技术处理等在镁合金表面改性方面的应用研究现状,对镁合金表面改性技术作综合评述。     

Al-Si基铸铝合金阳极氧化

Al-Si合金由于其良好的性能已在工业中得到了广泛的应用.阳极氧化成为铝合金铸件表面处理的一种重要方式,而阳极氧化膜色差直接影响到铸件的表面质量、使用寿命及外观要求.探讨了影响铸铝阳极氧化的因素,研究了铸铝合金的表面预处理和阳极氧化工艺,讨论了铸铝合金的表面预处理和工艺条件对阳极氧化膜性能的影响,据此优化工艺,获得了合适的表面预处理方法和阳极氧化最佳工艺条件.该工艺操作简便,节约能源,生产效率高,易于推广应用.     

镁合金表面处理研究现状及发展趋势

近年来,3C产业迅猛发展,节能环保成为全球关注的焦点,而减轻材料的重量和材料的循环利用是实现环保的重要手段.镁合金是最轻的工程金属材料之一,它具有良好的比强度、比刚度、可再循环和良好的铸造性能等特点,具有替代传统材料的广阔前景,被誉为21世纪绿色金属结构材料.但镁合金的耐蚀性差,严重阻碍了它的工业应用.因此,镁合金的表面防护处理极为重要.现在镁合金的表面处理工艺多种多样,良莠不齐.为了探索镁工业表面处理的最佳工艺,按照表面改性和表面涂层两大类系统地阐述了当今国内外镁合金表面处理的各种方法及其优缺点.最后,在综合前述处理工艺的基础上,提出了今后镁合金表面处理工艺的发展趋势.