Materials Forming and Control Engineering
你们专业有个姓邢的吧，我同学啊
我KAO，套妹子 你弄到没啊！
Composite Materials (Composite materials), is based on a matrix material (Matrix), a material for the reinforcement (reinforcement) material Performance on a variety of materials in each other, creating synergies, so that the integrated performance of composite materials than the original composition of material to meet a variety of different Matrix material is divided into two major categories of metal and non- Commonly used in metal matrix aluminum, magnesium, copper, titanium and its Mainly non-metallic matrix of synthetic resin, rubber, ceramics, graphite, carbon and so Main reinforcement glass fiber, carbon fiber, boron fiber, aramid fiber, silicon carbide fibers, asbestos fibers, whiskers, wires and other fine-grained and The use of composite materials can be traced back to ancient From ancient times to enhance the use of straw and clay for centuries has been the use of reinforced concrete formed by the two types of composite The 20th century, 40's, due to the needs of the aviation industry, the development of glass fiber reinforced plastic (commonly known as glass fiber reinforced plastic), a composite material from the After the 50's, have developed a carbon fiber, graphite fibers and boron fibers high strength and high modulus 70's a aramid fiber and silicon carbide These high-strength, high modulus fibers with synthetic resin, carbon, graphite, ceramic, rubber and other non-metallic substrate or aluminum, magnesium, titanium and other metal matrix composites, which constitute the composite material [Edit this paragraph] Classification Is a mixture of composite Composite materials into their component metals and metal composites, non-metallic composite materials and metals, non-metallic and non-metallic composite According to their structural characteristics are divided into: ① fiber composite Body will be placed in a variety of fiber-reinforced matrix--《复合材料学报》2004年05期
+Science&printsec=frontcover&source=web&ots=EYOdzukZQ7&sig=bskKId1Ujx5wNc8wLgAqP7KWILw材料科学 Materials ScienceMaterials science or materials engineering is an interdisciplinary field involving the properties of matter and its applications to various areas of science and This science investigates the relationship between the structure of materials and their It includes elements of applied physics and chemistry, as well as chemical, mechanical, civil and electrical With significant media attention to nanoscience and nanotechnology in recent years, materials science has been propelled to the forefront at many It is also an important part of forensic engineering and forensic materials engineering, the study of failed products and HistoryThe material of choice of a given era is often its defining point; the Stone Age, Bronze Age, and Steel Age are examples of Materials science is one of the oldest forms of engineering and applied science, deriving from the manufacture of Modern materials science evolved directly from metallurgy, which itself evolved from A major breakthrough in the understanding of materials occurred in the late 19th century, when Willard Gibbs demonstrated that thermodynamic properties relating to atomic structure in various phases are related to the physical properties of a Important elements of modern materials science are a product of the space race: the understanding and engineering of the metallic alloys, and silica and carbon materials, used in the construction of space vehicles enabling the exploration of Materials science has driven, and been driven by, the development of revolutionary technologies such as plastics, semiconductors, and Before the 1960s (and in some cases decades after), many materials science departments were named metallurgy departments, from a 19th and early 20th century emphasis on The field has since broadened to include every class of materials, including: ceramics, polymers, semiconductors, magnetic materials, medical implant materials and biological [edit] Fundamentals of materials scienceIn materials science, rather than haphazardly looking for and discovering materials and exploiting their properties, one instead aims to understand materials fundamentally so that new materials with the desired properties can be The basis of all materials science involves relating the desired properties and relative performance of a material in a certain application to the structure of the atoms and phases in that material through The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and the way in which it has been processed into its final These, taken together and related through the laws of thermodynamics, govern a material’s microstructure, and thus its An old adage in materials science says: "materials are like people; it is the defects that make them interesting" The manufacture of a perfect crystal of a material is currently physically Instead materials scientists manipulate the defects in crystalline materials such as precipitates, grain boundaries (Hall-Petch relationship), interstitial atoms, vacancies or substitutional atoms, to create materials with the desired Not all materials have a regular crystal Polymers display varying degrees of crystallinity, and many are completely non- Glasses, some ceramics, and many natural materials are amorphous, not possessing any long-range order in their atomic The study of polymers combines elements of chemical and statistical thermodynamics to give thermodynamic, as well as mechanical, descriptions of physical In addition to industrial interest, materials science has gradually developed into a field which provides tests for condensed matter or solid state New physics emerge because of the diverse new material properties which need to be [edit] Materials in industryRadical materials advances can drive the creation of new products or even new industries, but stable industries also employ materials scientists to make incremental improvements and troubleshoot issues with currently used Industrial applications of materials science include materials design, cost-benefit tradeoffs in industrial production of materials, processing techniques (casting, rolling, welding, ion implantation, crystal growth, thin-film deposition, sintering, glassblowing, ), and analytical techniques (characterization techniques such as electron microscopy, x-ray diffraction, calorimetry, nuclear microscopy (HEFIB), Rutherford backscattering, neutron diffraction, )Besides material characterisation, the material scientist/engineer also deals with the extraction of materials and their conversion into useful Thus ingot casting, foundry techniques, blast furnace extraction, and electrolytic extraction are all part of the required knowledge of a metallurgist/ Often the presence, absence or variation of minute quantities of secondary elements and compounds in a bulk material will have a great impact on the final properties of the materials produced, for instance, steels are classified based on 1/10th and 1/100 weight percentages of the carbon and other alloying elements they Thus, the extraction and purification techniques employed in the extraction of iron in the blast furnace will have an impact of the quality of steel that may be The overlap between physics and materials science has led to the offshoot field of materials physics, which is concerned with the physical properties of The approach is generally more macroscopic and applied than in condensed matter See important publications in materials physics for more details on this field of The study of metal alloys is a significant part of materials Of all the metallic alloys in use today, the alloys of iron (steel, stainless steel, cast iron, tool steel, alloy steels) make up the largest proportion both by quantity and commercial Iron alloyed with various proportions of carbon gives low, mid and high carbon For the steels, the hardness and tensile strength of the steel is directly related to the amount of carbon present, with increasing carbon levels also leading to lower ductility and The addition of silicon and graphitization will produce cast irons (although some cast irons are made precisely with no graphitization) The addition of chromium, nickel and molybdenum to carbon steels (more than 10%) gives us stainless Other significant metallic alloys are those of aluminium, titanium, copper and Copper alloys have been known for a long time (since the Bronze Age), while the alloys of the other three metals have been relatively recently Due to the chemical reactivity of these metals, the electrolytic extraction processes required were only developed relatively The alloys of aluminium, titanium and magnesium are also known and valued for their high strength-to-weight ratios and, in the case of magnesium, their ability to provide electromagnetic These materials are ideal for situations where high strength-to-weight ratios are more important than bulk cost, such as in the aerospace industry and certain automotive engineering Other than metals, polymers and ceramics are also an important part of materials Polymers are the raw materials (the resins) used to make what we commonly call Plastics are really the final product, created after one or more polymers or additives have been added to a resin during processing, which is then shaped into a final Polymers which have been around, and which are in current widespread use, include polyethylene, polypropylene, PVC, polystyrene, nylons, polyesters, acrylics, polyurethanes, and Plastics are generally classified as "commodity", "specialty" and "engineering" PVC (polyvinyl-chloride) is widely used, inexpensive, and annual production quantities are It lends itself to an incredible array of applications, from artificial leather to electrical insulation and cabling, packaging and Its fabrication and processing are simple and well- The versatility of PVC is due to the wide range of plasticisers and other additives that it The term "additives" in polymer science refers to the chemicals and compounds added to the polymer base to modify its material Polycarbonate would be normally considered an engineering plastic (other examples include PEEK, ABS) Engineering plastics are valued for their superior strengths and other special material They are usually not used for disposable applications, unlike commodity Specialty plastics are materials with unique characteristics, such as ultra-high strength, electrical conductivity, electro-fluorescence, high thermal stability, It should be noted here that the dividing line between the various types of plastics is not based on material but rather on their properties and For instance, polyethylene (PE) is a cheap, low friction polymer commonly used to make disposable shopping bags and trash bags, and is considered a commodity plastic, whereas Medium-Density Polyethylene MDPE is used for underground gas and water pipes, and another variety called Ultra-high Molecular Weight Polyethylene UHMWPE is an engineering plastic which is used extensively as the glide rails for industrial equipment and the low-friction socket in implanted hip Another application of material science in industry is the making of composite Composite materials are structured materials composed of two or more macroscopic An example would be steel-reinforced concrete; another can be seen in the "plastic" casings of television sets, cell-phones and so These plastic casings are usually a composite material made up of a thermoplastic matrix such as acrylonitrile-butadiene-styrene (ABS) in which calcium carbonate chalk, talc, glass fibres or carbon fibres have been added for added strength, bulk, or electro-static These additions may be referred to as reinforcing fibres, or dispersants, depending on their [edit] Classes of materials (by bond types)Materials science encompasses various classes of materials, each of which may constitute a separate Materials are sometimes classified by the type of bonding present between the atoms:Ionic crystals Covalent crystals Metals Intermetallics Semiconductors Polymers Composite materials Vitreous materials [edit] Sub-fields of materials scienceNanotechnology – rigorously, the study of materials where the effects of quantum confinement, the Gibbs-Thomson effect, or any other effect only present at the nanoscale is the defining property of the material; but more commonly, it is the creation and study of materials whose defining structural properties are anywhere from less than a nanometer to one hundred nanometers in scale, such as molecularly engineered Microtechnology - study of materials and processes and their interaction, allowing microfabrication of structures of micrometric dimensions, such as MicroElectroMechanical Systems (MEMS) Crystallography – the study of how atoms in a solid fill space, the defects associated with crystal structures such as grain boundaries and dislocations, and the characterization of these structures and their relation to physical Materials Characterization – such as diffraction with x-rays, electrons, or neutrons, and various forms of spectroscopy and chemical analysis such as Raman spectroscopy, energy-dispersive spectroscopy (EDS), chromatography, thermal analysis, electron microscope analysis, , in order to understand and define the properties of See also List of surface analysis methods Metallurgy – the study of metals and their alloys, including their extraction, microstructure and Biomaterials – materials that are derived from and/or used with biological Electronic and magnetic materials – materials such as semiconductors used to create integrated circuits, storage media, sensors, and other Tribology – the study of the wear of materials due to friction and other Surface science/Catalysis – interactions and structures between solid-gas solid-liquid or solid-solid Ceramography – the study of the microstructures of high-temperature materials and refractories, including structural ceramics such as RCC, polycrystalline silicon carbide and transformation toughened ceramics Some practitioners often consider rheology a sub-field of materials science, because it can cover any material that However, modern rheology typically deals with non-Newtonian fluid dynamics, so it is often considered a sub-field of continuum See also granular Glass Science – any non-crystalline material including inorganic glasses, vitreous metals and non-oxide Forensic engineering – the study of how products fail, and the vital role of the materials of construction Forensic materials engineering – the study of material failure, and the light it sheds on how engineers specify materials in their product [edit] Topics that form the basis of materials scienceThermodynamics, statistical mechanics, kinetics and physical chemistry, for phase stability, transformations (physical and chemical) and Crystallography and chemical bonding, for understanding how atoms in a material are Mechanics, to understand the mechanical properties of materials and their structural Solid-state physics and quantum mechanics, for the understanding of the electronic, thermal, magnetic, chemical, structural and optical properties of Diffraction and wave mechanics, for the characterization of Chemistry and polymer science, for the understanding of plastics, colloids, ceramics, liquid crystals, solid state chemistry, and Biology, for the integration of materials into biological Continuum mechanics and statistics, for the study of fluid flows and ensemble Mechanics of materials, for the study of the relation between the mechanical behavior of materials and their 材料科学材料是人类可以利用的物质，一般是指固体。而材料科学是研究材料的制备或加工工艺、材料结构与材料性能三者之间的相互关系的科学。涉及的理论包括固体物理学，材料化学，与电子工程结合，则衍生出电子材料，与机械结合则衍生出结构材料，与生物学结合则衍生出生物材料等等。材料科学理论物理冶金学 晶体学 固体物理学 材料化学 材料热力学 材料动力学 材料计算科学[编辑] 材料的分类按化学状态分类 金属材料 无机物非金属材料 陶瓷材料 有机材料 高分子材料 按物理性质分类 高强度材料 耐高温材料 超硬材料 导电材料 绝缘材料 磁性材料 透光材料 半导体材料 按状态分类 单晶材料 多晶质材料 非晶态材料 准晶态材料 按物理效应分类 压电材料 热电材料 铁电材料 光电材料 电光材料 声光材料 磁光材料 激光材料 按用途分类 建筑材料 结构材料 研磨材料 耐火材料 耐酸材料 电工材料 电子材料 光学材料 感光材料 包装材料 按组成分类 单组分材料 复合材料 [编辑] 材料工程技术金属材料成形 机械加工 热加工 陶瓷冶金 粉末冶金 薄膜生长技术 表面处理技术 表面改性技术 表面涂覆技术 热处理 [编辑] 材料的应用结构材料 信息材料 存储材料 半导体材料 宇航材料 建筑材料 能源材料 生物材料 环境材料 储能材料和含能材料 参考%E6%9D%90%E6%96%99%E7%A7%91%E5%AD%A6
吹塑，这里主要指中空吹塑 ( 又称吹塑模塑 ) 是借助于气体压力使闭合在模具中的热熔型坯吹胀形成中空制品的方法，是第三种最 常用的塑料加工方法，同时也是发展较快的一种塑料成型方法。吹塑用的模具只有阴模 ( 凹模 ) ，与注塑成型相比，设备造价较低，适 应性较强，可成型性能好 ( 如低应力 ) 、可成型具有复杂起伏曲线 ( 形状 ) 的制品。吹塑成型起源于 19 世纪 30 年代。直到 1979 年以后，吹塑成型才进入广泛应用的阶段。这一阶段，吹塑级的塑料包括：聚烯烃、工程塑料与弹性体；吹塑制品的应用涉及到汽车、办 公设备、家用电器、医疗等方面；每小时可生产 6 万个瓶子也能制造大型吹塑件 ( 件重达 180kg) ，多层吹塑技术得到了较大的发展； 吹塑设备已采用微机、固态电子的闭环控制系统，计算机 CAE/CAM 技术也日益成熟；且吹塑机械更专业化、更具特色。 1 吹塑成型方法 1 成型方法 不同吹塑方法，由于原料、加工要求、产量及其成本的差异，在加工不同产品中具有不同的优势。详细的吹塑成型过程可参考文献。 这里从宏观角度介绍吹塑的特点。中空制品的吹塑包括三个主要方法：挤出吹塑：主要用于未被支撑的型坯加工；注射吹塑：主要用于由 金属型芯支撑的型坯加工；拉伸吹塑：包括挤出一拉伸一吹塑、注射一拉伸一吹塑两种方法，可加工双轴取向的制品，极大地降低生产成 本和改进制品性能。此外，还有多层吹塑、压制吹塑、蘸涂吹塑、发泡吹塑、三维吹塑等。但吹塑制品的 75 ％用挤出吹塑成型， 24 ％ 用注射吹塑成型， 1 ％用其它吹塑成型；在所有的吹塑产品中， 75 ％属于双向拉伸产品。挤出吹塑的优点是生产效率高，设备成本低， 模具和机械的选择范围广，缺点是废品率较高，废料的回收、利用差，制品的厚度控制、原料的分散性受限制，成型后必须进行修边操 作。注射吹塑的优点是加工过程中没有废料产生，能很好地控制制品的壁厚和物料的分散，细颈产品成型精度高，产品表面光洁，能经济 地进行小批量生产。缺点是成型设备成本高，而且在一定程度上仅适合于小的吹塑制品。 中空吹塑的工艺条件，要求吹胀模具中型坯的压缩空气必须干净。注射吹塑空气压力为 55 ～ 1MPa ；挤出吹塑压力为 2l ～ 62MPa ，而拉伸吹塑压力经常需要高达 4MPa 。在塑料凝固中，低压使制品产生的内应力低，应力分散较均匀，且低应力可改进制品的 拉伸、冲击、弯曲等性能。 2 制品种类吹塑制品有容器、工业制件两类。其中容器包括：包装容器，大容积储桶 / 储罐，以及可折叠 容器。但随着吹塑工艺的成熟，工业制件的吹塑制品越来越多，应用范围也日益广泛。目前，容器约占 80 ％的市场份额，每年增长 4 ％ 左右；而工业及结构用制品占总量的 20 ％，每年增长速度为 12 ％。容器消耗量的增长在于可旋扭塑料容器的应用范围不断扩大，工业 用制品的消耗量增长主要是由新型加工技术的改进所致，如多层型坯挤出、双轴挤出、非轴对称吹塑等。表 2 列出了部分吹塑制品的应用 及其性能要求。 3 吹塑成型进展 (1) 原材料聚合物在成型过程中，首先通过口模时受高剪切力作用，然后物料呈现挤出膨胀及垂缩现象，在形成下垂的型坯时，其膨胀率 接近为零。接着型坯被吹胀紧贴在模具上，这时呈现低的膨胀率。过度的口模膨胀会产生废品。过度的垂缩导致制件的顶端到底部壁厚厚 度不均匀，严重的甚至不能成型。因此，在选择适合吹塑的聚合物时，必须弄清其剪切及膨胀的粘弹特性。 HDPE 由于热稳定性好，又有 多种改性产品，因而成为吹塑成型中应用最广泛的塑料。通过共聚和共混作用，对吹塑成型用原材料的研究在连续挤出吹塑级树脂方面也 取得了一些进展，如 PA6 、 PP 和 PET 。间歇式型坯吹塑成型，理论上适用于结构板材和大型制件的二次加工，要求使用工程塑料，如 阻燃型 ABS 、增强 PVC 、改性 PPO 和 PC 等，而这类挤出型塑料的耐高温性能一般较差，仅有少数树脂可在常规设备上吹塑成型大型制 件。在聚萘二甲酸乙二酯 (PEN)/PET 共混料吹塑成型时，需将防氧渗透和防水气渗透的树脂如 ( 乙烯 / 乙酸乙烯醇 ) 共聚物 (EVOH) 和 HDPE 与 PET 形成复合层，并产生锚联层，以改善 PEN/PET 料的渗透性和热稳定性。目前正研究将 HDPE 与 PA6 采用多层吹塑成型， 生产燃油油箱。 (2) 设备与工艺技术进展 吹塑机械设备已有很大的改进。较新的成果有： ①采用改进型红外加热技术进行再吹塑成型； ②非常高速的旋转挤塑压力，主要应用在牛奶瓶的生产上； ③模具附设在梭式压机上以补偿喷流现象； ④多层连续挤出吹塑成型防渗透性容器； ⑤通过对取向结晶和热结晶、预成型坯和模温、吹气压力，以及型坯在模腔内停留时间的严格控制，进行连续性热定形 PET 瓶的生 产。 由于市场对复杂、曲折的输送管材制件的需求，推动了偏轴挤出吹塑技术的开发，这种技术笼统称为 3D 或 3 维吹塑成型。 理论上，该工序十分简单，型坯挤出后，被局部吹胀并贴在一边模具上，接着挤出机头或模具转动，按已编的 2 轴或 3 轴程序转 动。难点在于要求具有非常大的惯性量的大型吹塑机械在高速合模时误差要低于 10 ％。多层吹塑成型工艺常用于加工防渗透性容器，其改进工艺是增设一个阀门系统，在连续挤出过程中可更换塑料原料，因而可交替生产出硬质和软质制品。生产大型制件如燃油箱或汽车外 结构板材时，在冷却过程中需降低模腔内压力以调整加工循环周期。解决方法是先将熔料储存在挤出螺杆前端的熔槽中，再在相当高速下 挤出型坯，以最大限度减少型坯壁厚的变化，从而确保消除垂缩和挤出膨胀现象。 储料缸式机头改进，使之能挤出热敏性塑料如 ABS — R 、改性 PPD 和 PVC 。而且，重新设计的机头，在生产中可快速装拆以方便 清理塑料，同时，对塑料的流变特性分析及计算机流道分析可设计流线型流道，以便于热敏性塑料的成型。 (3) 控制程序及吹塑模拟型坯的程序控制已有数十年的经验。 主要问题是型坯可拉坯变薄的最薄程度 ( 如瓶颈部位 ) ，增厚的型坯拉坯的最大程度 ( 如容器瓶体或边角部位 ) ，以及设计一个 壁厚度变化部位，例如凹边和瓶肩等。其工作重点应集中在所使用塑料的粘弹性特性上。对试管状的预成型坯壁厚的预测，也就是设计具 有防渗透作用的型坯最佳壁厚厚度的选择依据。这是由预成型坯的结晶程度，所使用塑料与温度相关的应力一应变弹性特性，以及由注塑 加工形成的冻结应力程度和分布等情况来决定的。 1980 年， GE 公司就为热成型和吹塑成型开发了： PITA 程序设计。 型坯吹塑成型的控制软件必须综合考虑如下因素：不均匀的型坯壁厚；型坯截坯口和环绕型吹塑管材截口；在合模前预先吹胀型坯； 吹胀过程控制和截坯口开设的部位；以及结构件吹塑成型中对型坯边缘的裁切定位等。目前，商业化的吹塑成型模拟软件主要有原美国的 ACTech 公司的 C — PITA 、比利时的 POLYFLOw 等。数值模拟的难度在于：大应变、非线性材料行为、接触问题以及膨胀过程中一些物 理非稳定性，而这些复杂性将导致产生一系列需要迭代求解的非线性方程。其中，材料、吹塑成型机理的研究一直是研究的难点、热点， 如拉伸吹塑被广泛应用，但对该过程的模拟所需要的应力诱导结晶的数学描述，到目前为止尚无合适的方法。而挤出吹塑的型坯，是聚合 物熔体流经环形模头时形成的，环形管道的几何形状和材料的粘弹性质将直接影响型胚膨胀，现有的粘弹性知识还无法描述这个过程。 与相对成熟的注塑 CAE 技术相比，吹塑成型软件目前正处于发展的初期阶段。 4 吹塑成型的发展趋势 吹塑将随着市场对其制品的需求，在材料、机械、辅助设备、控制系统、软件等方面有如下发展趋势。 (1) 原材料为满足吹塑制品的功能、性能 ( 医药、食品包装 ) 要求，吹塑级的原料将更加丰富，加工性能更好。如 PEN 类材料，不仅强 度高、耐热性好、气体阻隔性强、透明、耐紫外线照射，可适用于吹制各种塑料瓶体，并且填充温度高，对二氧化碳气体、氧气阻隔性能 优良，且耐化学药品。 (2) 制品包装容器、工业制品将有较大增长，而且注射吹塑、多层吹塑会有快速的发展。 (3) 吹塑机械及设备吹塑机械的精密高效化；辅助生产 ( 操作 ) 设备的自动化。“精密高效”不仅指机械设备在生产成型过程中具有较 高的速度和较高的压力，而且要求所生产的产品在外观尺寸波动和件重波动方面均能达到较高的稳定性，也就是说生产制品各个部位的尺 寸和外形几何形状精度高，变形及收缩小，制品的外观及内在质量和生产效率等指标均要达到较高的水准。辅助操作包括去飞边、切割、 称重、钻孔、检漏等，其过程自动化是发展的趋势之一。 (4) 吹塑成型模拟吹塑机理的研究更加深入，吹塑模拟的数学模型的合理构建，数值算法的快速、准确是模拟的关键，吹塑成型模拟将会 在制品质量预测、控制中发挥越来越重要的作用。 2 影响吹塑制品质量的因素及常见缺陷的排除 1 吹塑成型的影响因素 下面从吹塑成型过程分析各个阶段的成型参数。吹塑成型过程可分为四个阶段： (1) 型坯形成阶段聚合物在挤出机中的输送、熔融、混炼、泵出成型为型坯的形成阶段；在这一阶段，影响壁厚分布的主要工艺参数有： ①材料的分子量分布、平均分子量； ②吹塑机的温度控制系统和螺杆转速，其中温度控制系统包括料斗温度，料筒 1 区、 2 区、 3 区、 4 区温度，法兰温度，以及储 料模头 1 区、 2 区、 3 区、 4 区温度。 (2) 型坯下料阶段型坯从模唇与模芯的间隙中挤出为下料阶段。此时，型坯离模膨胀和型坯垂伸这两种现象影响型坯成型。影响壁厚分布 的主要工艺参数是吹塑机的模头直径和壁厚控制系统，其中控制系统包括轴向壁厚控制系统和周向壁厚控制系统，以调整模唇与模芯的间 隙。 (3) 型坯预吹阶段为避免型坯内表面的接触、粘附，改善制品壁厚的均匀性，要对型坯进行预吹胀。在型坯预吹阶段，从型坯下方往型坯 内喷气，以护持型坯，减小其垂伸。在这一阶段，影响壁厚分布的主要工艺参数有：预吹压力、预吹时间。 (4) 型坯高压吹阶段高压吹胀型坯，使之贴紧模具型腔，实现产品塑性成型阶段。该阶段，影响产品成型的是型坯受高压吹胀变形、型坯 与模腔接触变形。而影响壁厚分布的主要工艺参数有：材料的收缩率；吹气压力、时间；模具材料、结构、模具排气系统以及模具冷却系 统，如冷却水道分布、冷却水进水温度等。尽管影响吹塑制品质量的因素较多，但当生产条件、制品要求确定后，调整吹塑工艺参数能有 效改善制品质量。优化的工艺参数可以提高生产效率，降低原材料消耗，优化产品的综合性能。 2 吹塑成型工艺条件的设定 工艺条件调整的目的是，在满足产品最小壁厚要求的基础上，产品壁厚尽可能均匀，产品件重尽可能小 ( 减少材料消耗 ) 。工艺参 数设定的合理方法是，将经验与数值分析技术结合。基本过程为， ①利用已建立的计算机模型，模拟吹塑模具、下料型坯、夹料板等状态； ②输入各阶段对型坯壁厚分布影响的参数； ③对得到的模拟结果进行分析，通过计算机模拟显示哪些部位壁厚达不到要求，而哪些部位壁厚超厚； ④利用人工经验，调整输入的参数，重复①～③的过程，保证产品各部位在达到最小壁厚的前提下，尽可能减小产品各部位壁厚。 ⑤对多个工艺方案的结果分析、比较，最终确定优化的工艺参数。拉伸吹塑又称双轴取向吹塑，是在聚合物的高弹状态下通过机械方 法轴向拉伸型坯、用压缩空气径向吹胀 ( 拉伸 ) 型坯以成型包装容器的方法。拉伸吹塑有一步法、二步法。 3 吹塑成型常见的制品缺陷及其改进这里给出挤出吹塑成型、注射吹塑成型、拉伸吹塑成型常见的问题、产生的原因及解决办法。 (1) 挤出吹塑挤出吹塑是挤出成型最主要的成型方法。有连续挤出和不连续挤出两种方法。表 5 给出挤出吹塑常见制品缺陷及改进方法。 (2) 注射吹塑注射吹塑是先用注射法制成有底型坯，再将它吹移至吹塑模具中成型中空制品。注射吹塑可对制品进行精确的控制，能生产 无刮痕、精度高、表面光滑的制品，无需二次加工；其中制品的件重可控制在± 0 ． 1g ，螺纹的精度可为± 100 μ m 。注射吹塑常见制 品缺陷及改进方法见表 6 。 (3) 拉伸吹塑 3 结语 吹塑成型技术是随着塑料工业、机械制造等多种技术的进步而不断发展的，在吹塑产品的设计、生产过程中，不断融人现代设计思 想、设计工具，工程技术人员应充分利用先进的设计理念，结合人工经验，使制品设计、制造各个环节的效率提高，从而提高吹塑制品的 质量及市场竞争能力。
你还想要几篇，英文文献一篇平均6页以上，还要翻译？？？？？？？？？？
这方面的文章不太好写，你可以去找别人帮你写一下。他们的文章写的不错，完成文章,满意再付费的Q Q 好友查找一下就可以 一零三七二五二六五七材料是人类用于制造物品、器件、构件、机器或其他产品的那些物质。
俺这，应该有你要的
本科生怕什么，半个月可以搞定论文，实验只要做了，有数据，论文好写。硕士才悲催呢。。。
导师没有给你课题吗？根据课题找资料啥。
我先前也是对论文的写作非常非常头大，还好后来找轻风论文网的老师帮忙才搞定。论文里面的核心部分，分析和数据处理是最难的，包括我身边的一些同学写到一半写不下去了，我都介绍的 轻风论文网给他们，非常专业，有的甚至把整篇都找帮忙的
可以说选材是写人论文的一个坎儿，很多同学就摔倒在这里了，我们说选材创新不能只是塑造完美的人物，当然也要注意选材创新不等于描写社会阴暗面，总体来说，我们的文章都是要积极向上的。审卷老师讨厌那种大而空，而且不切生活实际的材料，如写父亲冒风雪骑着自行车送我去医院，这样的事情发生在21世纪几乎是不太可能，打的已经变得非常便利了
导师没有给你课题吗？根据课题找资料啥。
这方面的文章不太好写，你可以去找别人帮你写一下。他们的文章写的不错，完成文章,满意再付费的Q Q 好友查找一下就可以 一零三七二五二六五七材料是人类用于制造物品、器件、构件、机器或其他产品的那些物质。
本科生怕什么，半个月可以搞定论文，实验只要做了，有数据，论文好写。硕士才悲催呢。。。