铸造高温合金材料的加工方法研究

本文结合零件切削参数进行研究零件材料以及典型特征,对铸造高温合金材料的加工方法进行深入探讨,通过两种方法实现该种材料零件的制造,得出对铸造高温合金材料加工的最佳方法,找到提高铸造高温合金材料加工效率,降低制造成本的切削加工方法。     

X光检测方法在铸造零件中的应用

X光检测是近年来在铸造零件时进行缺陷预防和缺陷修正的新方法，X光检测在零件铸造中是完全自动的。既减少了人工消耗，又降低了由于人工的操作或不可避免的误差引起的零件的缺陷，提高了零件制各的精确度。本文对X光检测方法在铸造零件中的应用进行了详细的介绍。     

转杆加工工艺研究

本文研究了转杆的加工工艺方法和加工技巧,通过工艺分析和加工试验,攻克了转杆深孔加工精度难以保证、特殊螺纹加工及波纹的控制、螺纹喷丸表面质量控制等难题。介绍了特殊螺纹的加工和螺纹波纹控制方法,以及螺纹喷丸表面质量控制方法,加工出符合技术要求的转杆,完成了转杆加工工艺研究,有效提升了零件的制造水平,同时也为今后类似零件的研制提供技术支持。     

限位杆连接叉断裂原因分析

某拖拉机限位杆连接叉在进行空载提升试验时发生断裂,通过宏观观察、扫描电镜观察、金相检验、硬度测试、拉伸试验等方法对限位杆连接叉的断裂原因进行了分析。结果表明:限位杆连接叉原材料中的铝元素含量较高,在铸造凝固后的冷却过程中,铝元素与氮元素形成片状氮化铝夹杂物在原始奥氏体晶界位置析出,使材料的塑性和韧性大幅度降低,当受力过大时零件便会发生脆性断裂。     

提高某新机喷嘴加工合格率

某新机零件喷嘴是精密铸件,零件属于支架结构空间尺寸复杂;尺寸精度高t技术条件要求严格,细杆深孔加工出现零件壁厚超差的质量问题严重,本次针对以上问题,对工艺路线,毛料结构,工艺装备、加工方法进行了一系列的工艺改进,提高了零件加工合格率及试验合格率。     

SiC粒子增强铸造Al基复合材料的研制

本文用真空烘烤封罐法对 SiC 粒子进行预处理,在固液两相区内搅拌添加,制造了铸造 Al 基复合材料。测试表明,该复合材料具有铸造性能好,力学性能高的优点,适用于采用压铸、石膏型精密铸造、金属型铸造等工艺方法成型的活塞、连杆等要求苛刻的零件。     

一种可调入射角度的光学教学装置

一种可调入射角度的光学教学装置,其特征在于:包括基板、背板、摆杆、支架和激光笔,基板上竖直安装背板,该背板前端的基板上设置支架,该背板后端的基板上设置能左右限位摆转的摆杆,该摆杆上端部设置的激光笔发射端位于支架上方,在背板前端面上方设置与激光笔发射端相对位的入射角标尺,所述支架上能放置至少一个玻璃容器,在背板前端面设置与每个玻璃容器相对位的折射角标尺。     

钎焊在低温技术中的应用

实际上,钎焊已被应用于所有技术部门,它属于制造零件和装配件的先进方法之列。这些零件和装配件是由冲压、轧制、铸造和其它小边角料工艺过程所获得的最普通的毛坯加工制造而成的。钎焊的这一优点可用于研制高技术经济指标的结构。钎焊是低温技术产品制造的传统工艺过程。它之所以被广     

谈输油臂90°旋转弯头加工夹具设计

输油臂中具有许多弯头管道,其作用也各不相同,常用于高温、低温、强腐蚀性介质输送管道的连结。一般铸造成型。为了尺寸统一和提高生产效率,通常在数控车床上加工,但是该零件形状不规则,需要重复定位,装夹有一定的难度。根据加工需要,必须采用工装夹具进行装夹。文章主要阐述了该零件的工装设计制造。使用该工装缩短了装夹弯头零件的时间,大大提高了生产效率。     

SiC粒子增强铸造Al基复合材料的研究

用真空烘烤封罐法对SiC粒子进行预处理,在固液两相区内搅拌添加,制造成铸造Al基复合材料。测试结果表明,该复合材料具有铸造性能好,力学性能高,耐磨性能优良等优点。适用于压铸,石膏型精密铸造,金属型铸造等工艺方法成型的活塞、连杆等零件。     

Fixture design information support for integrated design and manufacturing

Although a vast amount of research has been conducted on developing computer-aided fixture design systems, the need for information exchange between the fixture design domain and other manufacturing domains has not been thoroughly dealt with. This paper addresses this gap in fixture design research through the development of appropriate information models for computer-aided fixture design systems to support integrated design and manufacturing. A fixture design activity model is presented that relates fixture design to other design and manufacturing activities. The implementation of the information models in XML and the exchange of the information models based on an XML messaging approach are also discussed.     

Isothermal transformation and decomposition ofβ 1 phase in a CuZnAl alloy

In the present paper, the crystallography of isothermal transformation and decomposition ofβ, phase have been studied by means of transmission electron microscopy and diffraction in the CuZnAl shape memory alloy. It has been proved that the bainite formed inβ ₁, matrix when the samples were transformed isothermally at moderate temperature. The crystallography of the isothermal bainitic transformation is identical to that of martensite in the same system. When the specimens were aged at moderate temperatures for longer time, the bainite and matrix decomposed to equilibrium phases. The decomposition process can be summarized as follows: $$\begin{gathered} bainite (9R) \to 9R + \alpha \left( {fcc} \right) \to \alpha + \beta \left( {bcc} \right) \hfill \\ matrix (B2) \to 2H + B2 \to \beta \left( {bcc} \right) \hfill \\ \end{gathered} $$ There are definite orientation relationships among these phases during the decomposition process and they are shown below: $$\begin{gathered} \left( {111} \right)_\alpha \parallel \left( {001} \right)_B ,\left[ {0\bar 11} \right]_\alpha \parallel \left[ {\bar 110} \right]_B \hfill \\ \left( {111} \right)_\alpha 5^ \circ away from \left( {110} \right)_\beta ,\left[ {0\bar 11} \right]_\alpha \parallel \left[ {1\bar 1\bar 1} \right]_\beta \hfill \\ \left( {110} \right)_M \parallel \left( {001} \right)_{2H} ,\left[ {001} \right]_M \parallel \left[ {010} \right]_{2H} \hfill \\ \end{gathered} $$ Thus, the crystallography of isothermal transformation and decomposition ofβ ₁ phase and the sequence of transitions have been revealed.     

Effect of weathering on the water sorption of GRP sheet material

Water sorption-desorption isotherms of glass-reinforced polyester (GRP) surface material, unweathered and weathered for periods of up to 6 1/2 years, have been determined over the entire relative vapour pressure range. The equilibrium sorbed water content of the weathered surface material is higher than that of the sheet exposed outdoors for the same length of time, by a factor of up to two. Also, the equilibrium sorbed water content of the degraded surface material increases with weathering time much faster than that of the GRP sheet. Isotherms of GRP sheet indicate that the equilibrium content of sorbed water is consistently higher in weathered samples than in unweathered sheet and is an increasing function of weathering time for periods of outdoor exposure of up to 7 1/2 years. The rates of water sorption and desorption of weathered GRP sheet, as assessed by the combined mean coefficient of diffusion \(\left[ {{1 \mathord{\left/ {\vphantom {1 {2\left( {\bar D_s + \bar D_d } \right)}}} \right. \kern-0em} {2\left( {\bar D_s + \bar D_d } \right)}}} \right]\) increase markedly with weathering time.     

RLS耐热铸造不锈钢燃烧器精密制造

RLS燃烧器是石油高新加热装备中的最核心关建零部件,铸件材质为耐热铸造不锈钢。燃烧器的内部形为状环状,是一个有8条细长窄缝的环形封闭室的压力容器,它的结构比较特殊,铸件壁厚也不均。而使用硅溶胶精密铸造工艺铸造,受熔模精密铸造工艺的局限性,模具制造、蜡件制造、模壳制造、铸件清理的制造工艺难度太大,产品的成功率很低。本文通过对铸件的铸造工艺性分析,汽腔被分割设计成汽腔芯和汽腔体,巧妙设计了汽腔芯的8条细长窄缝模具和制模工艺。通过先分后合工艺方法,解决了耐热铸造不锈钢燃烧器环形封闭汽室的细长窄缝蜡件和铸件的制造问题,使产品满足了要求。     

Microstructure studies of ZnO nanoneedles

ZnO nanoneedles with uniform diameter and length have been synthesized using thermal evaporation approach. Their microstructure and anisotropic growth mechanism have been studied by means of scanning electron microscopy, high-resolution electron microscopy and convergent-beam electron diffraction. The ZnO polarity induces fast [0001] axial growth of the ZnO nanoneedles which are directed either by high index and planes or by ZnO nanoparticle nuclei formed at the (0001)-Zn growth fronts. Moreover, the {0002} stacking faults are believed to assist the ZnO nanoneedle growth. The slope surfaces at the inactive -O bottom geometrically favor ZnO nanorods growth through twinnings.     

精铸型壳的增材制造技术研究进展

增材制造技术用于精密铸造领域,可以满足市场对精密铸件的短周期、个性化、多样化、柔性制造的需求.增材制造技术可以制作树脂模型代替蜡模进行精密铸造,但更高效的方法是用增材制造技术直接制备精铸型壳.目前可用于制备精铸型壳的增材制造技术主要有三维打印法(3DP)、选择性激光烧结法(SLS)、光固化成形法(SLA)以及浆料挤出法...     

Wet chemical etching of the (111)In and $$ \left( {\bar 1\bar 1\bar 1} \right) $$Sb planes of InSb substrates

This paper examines etching of the polar planes (111)In and $ \left( {\bar 1\bar 1\bar 1} \right) $ \left( {\bar 1\bar 1\bar 1} \right) Sb of InSb wafers for liquid phase epitaxy in various etchants after mechanical and chemomechanical polishing. We describe procedures for polishing wafers and removing residual abrasive particles from the surface of polished wafers. A tartaric-acid-based etchant is shown to ensure a mirror-smooth finish of the $ \left( {\bar 1\bar 1\bar 1} \right) $ \left( {\bar 1\bar 1\bar 1} \right) Sb surface, with no visible oxidation. Etching of the (111)In surface with a lactic-acid-based etchant produces planes inclined to the parent surface at an angle close to the misalignment angle between the surface and (111) plane.     

增材制造技术在航空铸造领域的应用

增材制造技术是一种兼顾精准成型和高性能的一体化制造技术,其产品因生产周期短、成本低和复杂结构构件制备等方面的优势而备受关注,在多个领域都有所应用。铸造技术作为一种典型的传统工艺,在复杂结构构件和大型件制造方面也具有独特优势,即使在材料加工技术日新月异的今天也无法被取代,但铸造技术也因为长周期、复杂成型件的冶金及尺寸缺陷控制困难等因素的限制,需要谋求新的工艺发展方向。对于航空铸件而言,缩短研制周期,提高冶金质量尤为重要,本文旨在探讨增材制造技术在航空铸件制造方向的应用,将增材制造技术与传统的铸造技术进行深度融合,实现航空铸件短周期、低成本、高性能、精确成型和功能优先设计。     

白车身制造尺寸质量控制中的软测量方法

在白车身制造尺寸质量控制过程中,主要采用样架、三坐标测量机(CMM)、在线三坐标测量机(OCMM)进行检测。比较三者,样架和CMM测得的数据“点多量少”(测点很多,每个测点每天有1到2个数据),而OCMM测得的数据“点少量多”(测点相对较少,每个测点每天有200个左右数据)。采用软测量的方法,可使CMM测量数据和OCMM测量数据进行互补,达到精确评价车身制造质量的目的。     

铸件凝固过程的宏观及微观模拟仿真研究进展

面向市场经济,迎接全球化竞争的挑战,为国民经济的发展作贡献,就要十分重视制造业特别是铸造行业的发展。但是,我国铸造行业与国外相比有很大差距,它制约着国民经济的发展。世界各国在铸造成形加工技术的发展趋势方面,认识是一致的,即：一是大型工程中特大型铸件的关键铸造技术;二是向精确成形技术方向发展;三是用计算机模拟仿真逐步代替传统的经验性研究方法。铸造过程计算机模拟仿真是改造传统铸造产业的必由之路,是当今世界各国专家学关注的热点。铸造充型凝固过程的数值模拟可以帮助工程技术人员优化工艺设计,缩短试制周期、降低生产成本、确保铸件质量,已成为铸造领域最热门的研究课题之一。目前,凝固过程的流场、温度场数值模拟及缩孔缩松预测已应用于实际生产,应力分析、微观组织模拟等方面的基础研究及实用化进程都取得了很大进展。