某航空发动机分油套筒砂型铸造工艺研究

针对某航空发动机分油套筒铸件(下述简称铸件)存在冶金质量缺陷的问题,结合铸件结构和镁合金性能特点,分析了其质量缺陷的成因。立足于原有浇注系统,制定了增加浇道过滤网、合理搭配激冷冷铁、采用倾斜浇注及增加冒口尺寸等改进措施,对浇注系统和工艺资料进行了完善,并进行了试验验证。结果表明,铸件内部质量缺陷已消除,产品合格率大幅提高。     

筒管类铸钢件的铸造工艺

筒管类铸钢件一般有两种铸造方案,即直立浇注和水平浇注,可根据具体条件选用。 (1)直立浇注 铸件浇注时处于直立位置,在铸件顶部安放冒口进行补缩,自下而上顺序凝固,一般采用底注式或阶梯式两种浇注系统,只要合理选择浇注系统和冒口系统,就能够获得内部组织致密的合格铸件,但需要较大的冒口和补贴,其工艺     

铝合金框架铸造工艺研究

介绍了该铝合金框架零件的结构特点,并通过工艺分析选择了恰当的砂型铸造生产方式进行小批量铸造生产。通过计算机铸造工艺模拟,验证了铸造工艺的合理性与铸造工艺方案的可行性。     

高铬铸铁件金属型—砂型复合铸造工艺

采用金属型－砂型复合铸造工艺生产高铬铸铁件,可提高铸件的表面和内在质量,是提高板锤抗磨性,延长其使用寿命的有效措施。     

用普通水玻璃砂铸造高精度齿条工艺方案的优化

齿条的齿部尺寸精度和表面平整度要求较高,采用普通水玻璃砂手工生产方式铸造难度很大,试制过程往往解决了一些问题又出现一些新的问题,在不断的实践摸索中,我们终于找到最优工艺方案。采用该方案生产出2640件齿条,全部符合质量要求。     

大型紫铜件的铸造工艺

结晶轮是连铸机的重要零件,要求有优良的导热性和良好的热疲劳性,紫铜是制作结晶轮的理想材料。我们曾和工厂合作,用紫铜进行半金属型铸造获得成功,现将其铸造工艺简介如下。 1.铸造工艺方案 (1)铸件结构见图1。 (2)铸型结构如图2所     

铸造铝合金件的工艺设计及优化

正近年来,我国铸造业正向铸造强国的方向发展,铸造产业也将迎来一次新的变革,在铸造工艺设计上趋向于计算机技术的应用,在铸造材料上也趋于高强度轻量化特点。其中铸造铝合金是我国铸造业重点发展的新型材料,同时它也将被广泛用于其他行业,尤其在汽车、航空等行业,有很大的发展前景。铝合金为传统的金属材料,密度小,强度高,流动性好,熔炼温度低,特别适用于金属型铸造、压铸、挤压铸造。但对于单件小批生产,若采用金     

离心铸造MC尼龙管道脱模装置机械手的设计

对离心铸造MC尼龙管道在生产过程中的工艺原理进行研究,设计了一套自动脱模装置,主要针对自动脱模机械手的功能和结构进行了设计,并对其脱模过程中的脱模力进行了理论分析和计算。同时,利用有限元分析技术,对MC尼龙管道在机械手夹持下脱模时产生的应力、应变进行了分析,其结果表明,机械手对管道施加的脱模力不会引起管道的变形,从而验证了该装置机械手设计方案的可行性,而且该套脱模装置可以适用于不同管径的管道,同时还可以实现自动化。     

复杂曲面微小零件切削加工工艺研究

随着微机电和纳米技术的快速发展,复杂形面微小零件的加工显得越来越重要。本文对复杂形面微小零件的精密切削工艺进行了分析,重点探讨了微细切削加工机理、刀具选择、刀具路径规划以及切削用量的选择。     

超精密切削的复杂曲面微加工研究

随着微机电和纳米技术的快速发展,复杂形面微小零件的超精密加工显得越来越重要。本文通过对复杂曲面超精密加工的研究,针对金属材料制作的复杂形面微小零件的超精密切削工艺进行了深入研究。     

复杂陶瓷型芯增材制造及浇注工艺验证

针对多层内腔空心涡轮叶片用复杂陶瓷型芯,研究基于光固化的陶瓷型芯增材制造方法.采用光敏树脂与熔融石英粉混制的陶瓷浆料,通过DLP增材制造设备进行陶瓷型芯坯体制备,再经过脱脂烧结工艺获得可用于实际浇注的陶瓷型芯.光敏树脂活性单体选用1,6-己二醇二丙烯酸酯(1,6-hexanediol diacrylate,HDDA)和...     

ZnOw填充铸型尼龙复合材料滚动摩擦磨损行为

研究ZnOw填充铸型尼龙(MC)复合材料的滚动摩擦学性能.结果表明,ZnOw/MC复合材料的拉伸强度随氧化锌晶须含量增加而升高,而断裂伸长率随氧化锌晶须含量的增加而降低;ZnOw/MC复合材料的摩擦因数和磨损率均随氧化锌晶须含量增加而降低;随着氧化锌晶须填充量的增加,磨损.ZnOw/MC复合材料的磨损机制由黏着磨损变为疲劳     

航空复杂件精铸蜡模数控成型新工艺

提出采用多轴数控铣削加工工艺直接得到适合精度要求的航空复杂件的精密铸造用蜡模,克服了有模蜡模制造周期长、成本高及无模蜡模快速成型精度低的缺点,实现了航空复杂件精铸蜡模的无模快速精确成型,更好地满足了新机研制对于航空复杂件少量快速高精度的要求,对于航空工业的发展意义重大。     

Torsional Wear Behavior of MC Nylon Composites Reinforced with GF: Effect of Angular Displacement

The torsional wear behavior of monomer cast nylon (MC nylon) composites reinforced with glass fiber was studied with a self-made torsional friction tester. The worn surface of MC nylon composites was investigated with a scanning electron microscope. The worn surface of the steel disk was observed with a 3-D profiler. The experimental results indicated that the shape of torque–angular displacement (T–θ) curves changed from elliptic shape to quasi-parallelogram with the angular displacement increased from 5° to 30°. The serious wear characterized with a deep groove occurred at the position of about 1.5–4 mm radius of contact zone on the steel surface. The mass of MC nylon samples increased after torsional wear test. The torsional contact area can be divided into three zones: (a) a central stick zone, (b) an intermediate mixed-slipping annulus, and (c) a peripheral sliding annulus. The most serious wear occurred in the intermediate annulus because of the higher contact stress and mixed slip regime. The main wear mechanism of MC nylon samples was adhesive wear and abrasive wear. Plastic deformation of asperities was the character in the central zone. Slight adhesive wear was the main wear mechanism in the peripheral annulus.     

LiCl对PA6溶液络合改性研究

采用LiCl对PA6进行溶液络合改性,通过红外光谱(IR)、差示扫描量热法(DSC)研究了LiCl含量对PA6改性程度的影响。研究表明,随着含量的增加,LiCl对PA6络合改性的程度加大,改性PA6的结晶温度及结晶度逐渐下降;当LiCl含量达到7%以后,改性PA6已转变成无定型状态。     

玻璃微珠填充改性含油铸型尼龙的摩擦学和热性能

以玻璃微珠为填料制备了玻璃微珠填充改性含油铸型尼龙复合材料,研究了复合材料的摩擦争性能和热性能。结果表明：加入玻璃微珠的复合材料的摩擦因数降低,耐磨性提高,其磨损行为主要是粘着磨损和磨粒磨损;该复合材料的热变形温度有所降低,但线膨胀系数减小。     

Triboelectrification Electrostatic Potential of MC Nylon 6 under Point Contact Dry Sliding

The triboelectrification electrostatic potential of MC nylon 6 and its influence factors have not been investigated to date. Here, we report on our study of the interaction of tribological behaviors and triboelectrification electrostatic potential for the prevention or application of triboelectrification. The equipment we used to polymerize insulation materials and for instantaneously monitoring the dynamic variations of triboelectrification electrostatic potential, friction coefficient, and temperature at the tribo-interface was self-designed. The dynamic variations in the triboelectrification electrostatic potential of the polymer insulation materials under dry sliding were investigated using this equipment. An obvious influence on magnitude and change tendency of the triboelectrification electrostatic potential of MC nylon 6 could be produced only when the combined action of load (P) and speed (V) made PV values reach a certain degree. After MC nylon 6 rubbing against the bearing steel, the triboelectrification electrostatic potential of MC nylon 6 was not constant, and it could even abruptly drop from hundreds of volts to 0, especially under severe sliding conditions. A positive charge existed on the tribo-surface of MC nylon 6 and a negative charge existed on the tribo-surface of the counterpart steel. During the severe wear process, the experimental conditions, wear rate, the formation of transfer film, and the fraction of film on the counterpart as well as frictional heat were the most significant interaction effects on the abrupt change in the triboelectrification electrostatic potential among all factors studied. The interaction of tribological behaviors and triboelectrification electrostatic potential was clearly not a simple physical mechanism, which might be influenced by the external conditions and internal integration.