铝合金建筑型材生产实践

介绍了６０６３铝合金建筑型材的生产工艺。对其淬火敏感性、停放效应和制品折典型缺陷进行了讨论。     

我国铝合金建筑型材工业状况

评述了我国铝合金建筑型材的生产设备状况、装机水平、产能与分布、型材质量和经济效益情况,探讨了我国铝合金建筑型材今后的发展方向。     

铝合金建筑型材粉末涂料静电喷涂

在金属表面处理技术中,粉末涂料静电喷涂技术发展较晚,但与阳极氧化着色技术相比有许多优点,很有发展前途。本文介绍用在铝合金建筑型材上的这种技术的原理,工艺,所需设备及其检验等有关事项。     

6063-T5铝合金建筑型材生产工艺优化

对6063－T5铝合金型材的化学成分控制、熔铸、均匀化、挤压和热处理工艺等进行了优化分析，提出了提高其力学性能、表面质量和生产效率的技术措施。     

带锯机锯切铝合金铸件冒口

通过设计与制作锯切工装，将铝合金铸件——泵轮的大冒口在木工带锯机上锯切，不仅减轻了原手工锯切所需很大的劳动强度，而且提高工效近10倍，同时也使带锯机有了新的用途。     

铝合金建筑型材的质量参数及其检测方法

根据最新审定的国家标准ＧＢ５２３７《铝合金建筑型材》和ＧＢ８０１３《铝及铝合金阳极氧化－阳极氧化膜的总规范》,介绍了建筑型材的主要质量参数、合格要求及检测方法,分析了各种检验方法之间的关系。结论是生产企业应进行全部７项必检参数的检验;使用单位可进行外观,壁厚和尺寸偏差,硬度及膜厚４个项目的检验;质量监督单位可优先开展壁厚,硬度和膜厚３个项目的监管工作。     

铝合金空心建筑型材的焊合纹

介绍了6063铝合金空心建筑型材经表面处理后焊合区表面产生焊合纹的组织特征、形成机理。指出；焊合纹有白亮色和暗色带状物两种；形成两种焊合纹，存在带状分布质点、小晶粒和织构等3种组织特征；焊缝区金属变形程度大是产生焊合纹的关键；改善模具设计，减少焊缝区局部变形是减少焊合纹的主要措施。     

铝合金建筑型材金黄色电解着色的工艺研究

介绍了铝合金建筑型材金黄色电解着色的工艺，将阳极氧化后的铝合金制品在含有高锰酸钾、OBO-14添加剂、硫酸的槽液中进行交流电解，给出了着金黄色的最佳工艺参数。     

铝合金建筑型材的发展

铝合金建筑型材广泛应用于各种商业及民用建筑,其质量及产品安全直接涉及到国家公共安全与千家万户的利益,因此,我国对铝合金建筑型材实施工业产品生产许可证管理。经过20多年的发展,铝合金建筑型材工业在总量快速增长的同时,产品质量不断提高,产业逐渐走向成熟。     

铝合金建筑型材的发展

铝合金建筑型材广泛应用于各种商业及民用建筑,其质量及产品安全直接涉及到国家公共安全与千家万户的利益,因此,我国对铝合金建筑型材实施工业产品生产许可证管理。经过20多年的发展,铝合金建筑型材工业在总量快速增长的同时,产品质量不断提高,产业逐渐走向成熟。     

对中国铝挤压工业若干问题的探讨

经过48年来的发展中国铝挤压工业成就辉煌，举世瞩目，已成为全球最大的铝材挤压大国与消费大国，成为挤压铝材强国的时日也为期不远了。2003年中国挤压铝材的产量2335kt，消费量1980kt；中国是一个挤压铝型材净出口国，2003年的净出口量为219．24kt。尽管如此，但仍存在一些具有挑战性的问题，诸如：产业结构不合理，研发力量薄弱，能源消费大，低水平重复建设仍在发展，伪劣产品屡禁不止等等。这些问题当然会在今后不断完善的中国社会主义市场发展中得到解决，如果对它们的不足之处有充分的认识并加以妥善解决，就会缩短问题存在的期限，使中国早日跻身世界铝材挤压强国之林。     

GB/T5237-2000<铝合金建筑型材>标准评述

全面介绍和分析了我国新制订的铝合金建筑型材国家标准内容与质量指标水平。详细阐述了ＧＢ／Ｔ５２３７．１－２０００～ＧＢ／Ｔ５２３７．５－２０００（基材、阳极氧化、着色型材、电泳涂漆型材、粉末喷涂型材、氟碳漆喷涂型材）适用范围、标准水平及其主要技术指标制定的依据、参照标准、检验项目、测试方法和应用等。     

The measurement of pressure and level of fill in sealed storage drums

A non-intrusive technique has been developed which will detect an increase in pressure over ambient levels and alert workers of potential danger. Pressurization within the drum can be detected by measuring the frequency at which the drum lid vibrates; the natural frequencies increase as the pressure increases. It is shown that at high levels, the level of fill affects the frequency of the fundamental mode, but affects the higher modes to a much lesser degree. Thus, by measuring the frequencies of the fundamental and the first axisymmetric modes, the effect of fill level can be separated from pressurization. Analytical and experimental results are presented, along with suggestions for implementation.     

Microstructure, Texture and Mechanical Properties of Extruded Mg-Zn-Zr Mg Alloy Profiles

通过X射线衍射分析、金相分析和力学性能测试对大尺寸ZK60镁合金挤压型材的微观组织、织构取向和室温力学性能进行系统研究。结果显示,挤压态ZK60镁合金中主要由α-Mg和Mg Zn2相组成,此外还有少量的Mg2Zn11和Zn2Zr3相。挤压变形后初始的粗大铸态组织沿着挤压方向被极大地细化和破碎,同时伴有部分动态再结晶发生。大部分晶粒的基面沿着挤压方向和横向排列而不是常规的挤压纤维状取向分布。沿着45o方向取样展现出最好的断裂伸长率,其中间和边部分别为28%和23%,而最大抗力强度则体现在沿着挤压方向拉伸样品在中间和边部分别为325和312 MPa。     

高档数控机床动态性能评价研究

为全面准确地评价高档数控机床的性能,需要在准静态精度评价的基础上增加动态性能方面的评价。根据零件高质量、高效率加工要求的特点,提出高档数控机床动态性能评价体系;从时域和频域两个方面确定具体评价指标,并应用模糊综合法建立动态性能量化评价模型;以3台大型铣齿机床动态性能的评价为例,验证了所提方法的可行性。分析表明,该方法能有效弥补机床传统评价方法的不足。     

挤压态6061铝合金的力学性能及显微组织

对挤压态6061铝合金分别进行了固溶处理和时效处理,采用万能试验机测试了其力学性能,通过SEM和TEM表征了合金的微观组织,研究了不同热处理条件下挤压态6061铝合金的组织演变规律。结果表明:固溶和时效处理后的挤压态6061铝合金均表现出明显的力学性能各向异性,且时效处理能有效提升合金的强度;同时,经时效处理后的挤压态6061铝合金表现出应变速率敏感性,而固溶处理的挤压态6061铝合金则无明显的应变速率敏感性;固溶处理和时效处理的挤压态6061铝合金的晶粒形态为等轴晶,但是有大小两种晶粒尺寸等级,大晶粒尺寸可达200 μm,小晶粒尺寸则小于10 μm。固溶和时效处理的挤压态6061铝合金均由较强的{001}<100>立方织构和较弱的{011}<100>高斯织构组成,且种类和强度相同;拉伸变形后的6061铝合金出现了大量的位错堆积,而经时效处理的合金中均匀分布短棒状的析出相能有效阻碍位错的运动,提高材料的变形抗力。     

Parametric study on the impact-echo method using mock-up shafts

In this study, the impact-echo method was employed to evaluate the integrity of shafts, and parametric simulations of the impact-echo method were carried out numerically and experimentally. A one-dimensional finite element study was performed for mock-up shafts that include solid and damaged shafts. The mock-up shaft was made of Monocast, and four types of flaws were considered: (1) axisymmetric voids, (2) non-axisymmetric voids, (3) necks, and (4) bulbs. The reduction in shaft cross-sectional area varied from 30 to 80%. Subsequently, experimental studies were carried out to verify the finite element models using similar mock-up shafts. These experimental studies were carried out in the air and soil, and impact responses were analyzed in both time and frequency domains. It was shown that the results of the experiment were in agreement with those of numerical studies, and the accuracy of the impact-echo method was influenced by the type, size and location of flaws. In addition, it was also revealed that axisymmetric void, non-axisymmetric void, and neck could be detected in the frequency domain when the reduction in shaft cross-sectional area was more than 50%. Alternatively in the time domain, it was possible to identify the flaw reliably when the reduction was 30%. This latter approach provides the better possibility of detecting smaller flaw in shaft.     

轴向柱塞泵振动噪声诊断分析与研究

对某型轴向柱塞泵的振动异响噪声原因进行了分析与研究。开展了轴向柱塞泵振动测试试验,搭建了振动测试试验台并进行多点振动功率谱测试,进行了柱塞泵的理论输出压力、流量脉动,时域、频域特性分析,以及结构件模态仿真分析。通过试验和仿真结果的对比分析,定位了泵-试验台系统的噪声来源,明确了产生原因,提出了消除噪声的方法。     

Time domain simulation of torsional–axial vibrations in drilling

A time domain model of the torsional–axial chatter vibrations in drilling is presented. The model considers the exact kinematics of rigid body, and coupled torsional and axial vibrations of the drill. The tool is modeled as a pretwisted beam that exhibits axial and torsional deflections due to torque and thrust loading. A mechanistic cutting force model is used to accurately predict the cutting torque and thrust as a function of feedrate, radial depth of cut, and drill geometry. The drill rotates and feeds axially into the workpiece while the structural vibrations are excited by the cutting torque and thrust. The location of the drill edge is predicted using the kinematics model, and the generated surface is digitized at discrete time intervals. The distribution of chip thickness, which is affected by both rigid body motion and structural vibrations, is evaluated by subtracting the presently generated surface from the previous one. The model considers nonlinearities in cutting coefficients, tool jumping out of cut and overlapping of multiple regeneration waves. Force, torque, power and dimensional form errors left on the surface are predicted using the dynamic chip thickness obtained from the exact kinematics model. The stability of the drilling process is also evaluated using the time domain simulation model, and compared with extensive experiments. This paper provides details of the mathematical model, experimental verification and simulation capabilities. Although the surface finish from unstable cutting can be predicted realistically, the actual drilling stability cannot be determined without including process damping.