表面处理技术在模具制造中的应用和发展

简要地概述了表面处理技术在提高模具质量中的作用,按物理表面处理法、化学表面处理法和表面覆层处理法对模具表面处理技术进行了综述。最后指出了表面处理技术在模具发展中的重要作用。     

齿轮模具——激光表面强化工艺与装备技术进展

齿轮模具激光表面强化技术是指在数控环境下，利用高能量密度的激光束和涂料或熔覆材料对齿轮或模具表面进行处理，改变其表层的组织或成分，实现表面相变强化或增强性修复的技术。     

我国轮胎模具制造和清洗技术概况

介绍我国轮胎模具的制造和清洗技术.轮胎模具在制造过程中的表面处理尤为重要,利用稀土复合渗表面处理技术可以以国产碳素塑料模具钢和低合金塑料模具钢替代昂贵的高合金精密塑料模具钢制造轮胎模具,大大降低生产成本.模具清洗方法中以干冰清洗法效果最佳,可在不损伤模具和无污染的前提下清洗细小的排气孔,并大大降低操作人员的劳动强度.     

浅论模具的表面处理技术

文章阐述了几种表面处理技术和应用情况。实践证明，表面强化处理是模具强化处理的最新技术和有效手段，应该大力发展和推广。     

模具抛光、强化和修复新技术

北京国际科技服务中心推出当代先进水平的型腔模具抛光、强化和修复新技术。该技术应用电化学沉积的原理,在室温下使工件表面快速沉积成一层硬度大和耐磨、耐腐蚀极强的超细晶粒或非晶态金属,大大提高了模具的使用寿命;对破损、尺寸超差的模具和工件进行修复,使报废的模具再生使用,可节约大量材料和资金。该技术是大幅度提高材料表面综合性能的新工     

橡胶模具激光清洗的工艺研究

激光清洗模具的原理是利用模具基体物质与表面附着的污垢对某一频率的激光能量吸收系数的差别,使激光能量充分被表面附着的污垢所吸收,从而受热膨胀直至气化,所形成的气体被吸收利用而不损伤模具甚至强化模具基体,以达到绿色清洗的目的。本文从橡胶模具表面颗粒受力、激光清洗的机理与主要性能参数及其光路控制,对激光加工技术的应用进行了探讨。     

大型模具的表面强化

1大型模具强化的意义 模具是各工业部门的重要工艺装备,其使用性能直接影响到产品的升级换代及在国际市场上的竞争能力[1].大型模具作为模具的一种特例,在整个制造业中有着举足轻重的作用.以广州本田厂为例,现在生产一种车型需要大型模具100套左右.如果通过表面强化的方法使其寿命提高一倍,不仅可以节约100套模具的制造费用,而且可以大大减少因未强化处理所需要的修模费用及停工损失等.     

专利文摘

液压硫化机模具支承装置;轮胎模具五元共渗表面强化处理设备;改良的注塑机;塑料正压成型机;熔体泵挤出机.     

控提高冷作模具耐磨性的物理实验研究

影响模具耐磨性的因素是多方面的,本文通过摩擦磨损实验及生产实例指出科学地选择模具材料、模具表面强化工艺、润滑可以大幅度提高模具的耐磨性。     

铸铁件电刷镀的前处理探讨

0前言 汽车大型成形模具因结构复杂,难以机械加工,一般采用整体铸造。但铸铁不耐磨,磨损后修复也不容易,为了提高模具寿命,需要在模具表面施加强化层。采用电镀对表面进行强化还存在一些问题,如：镀层不均匀,镀后修正工作量大,需要大功率电源及专用的吊装设备等。而采用电刷镀的方法可以直接在生产现场进行模具强化,     

含氟硅聚苯并噁嗪材料的制备及其表面性能

本文合成了含氟硅氧烷苯并噁嗪单体,在采用光学显微镜等考察水解沉积条件对单体在羟基化基片表面化学成膜的影响的基础上,考察了温度、时间等对聚苯并噁嗪成膜后表面能的影响,并对聚苯并噁嗪材料在不同热处理温度（100℃-350℃）下表面能的热稳定性能进行了研究。结果表明用pH=2的盐酸溶液调节沉积液所得单体膜最均一完整,聚合物的表面能随着固化时间的增加先降低后升高,固化温度越高,达到完全固化所需要的固化时间越短,在160℃,190℃,220℃,240℃下固化所得聚合物最低表面能分别是15.6 mJ?m-2 (4 h),15.0 mJ?m-2 (1 h),15.3 mJ?m-2 (15 min),15.5 mJ?m-2 (5 min),均低于Teflon的表面能（22.0 mJ?m-2）。聚合物膜表面能在低于200℃的温度下处理其表面能可基本保持不变,可以作为抗粘材料应用于纳米压印技术中。     

Dynamic mold surface temperature control using induction heating and its effects on the surface appearance of weld line

Electromagnetic induction heating combined with coolant cooling is used to achieve dynamic mold surface temperature control. A simulation tool was also developed by integration of both thermal and electromagnetic analysis modules of ANSYS, and capability and accuracy were verified experimentally. To evaluate the feasibility and efficiency of induction heating on the mold surface temperature control, a mold plate (roughly about an inset size of cellular phone housing) with four cooling channels was utilized for two demo experiments with varying mold surface temperature between 110 and 180°C, and 110 and 200°C, respectively. During induction heating/cooling, it takes 4 s to increase mold surface temperature from 110 to 200°C and 21 s for mold surface to return to 110°C. The mold plate surface temperature can be raised at about 22.5°C and cooled down at 4.3°C/s within the aforementioned temperature range. Mold plate temperature distribution exhibits good uniformity as well in all stages of the heating/cooling process. Finally, mold surface temperature of a double‐gated tensile test part mold was induction heated to above glass transition temperature for few seconds prior to melt injection. The surface mark of weld line was eliminated, and the associated weld line strength enhanced. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1174–1180, 2006     

Experimental investigation of infrared rapid surface heating for injection molding

A low cost and practical infrared rapid surface heating system for injection molding is designed and investigated. The system was designed to assemble on the mold and a control system was used to operate the motion of the lamp holder. Four infrared halogen lamps (1 kW each) were used as the radiative source to heat the surface of mold insert. The temperature increase is verified on the mold plate with a thermal video system. Two types of specular reflectors combined with different bulb configurations were applied to study the heating ability of radiation heating. A modified spiral flow mold was used to test the enhancing filling ability of the rapid surface heating system. Three resins, PP, PMMA and PC were molded in the spiral flow injection molding experiments. If spherical reflector and centralized lamp configuration are used, the temperature at the center of the mold surface is the highest. The temperature of mold center surface is raised from 83°C to 188°C with 15 s of infrared heating. Because the surface temperature of the mold insert is higher than the glass transition temperature of resins before filling, the flow distance of resins in the modified spiral flow mold will be increased. The location effect of the infrared surface heating system on a thin‐long cavity was studied to demonstrate the possibility of using smaller infrared heating area on a large mold surface. A microprobe cavity also demonstrated that with the assistance of infrared heating technology the formability of a microprobe can be greatly improved. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3704–3713, 2006     

High‐frequency proximity heating for injection molding applications

High‐frequency proximity heating was used to rapidly heat injection molds. The principle is based on the proximity effect between a pair of mold inserts facing each other with a small gap and forming a high‐frequency electric loop. Because of the proximity effect, the high‐frequency current will flow at the inner surfaces of the facing pair, thus selectively heating the mold surface. With this method, the electrical insulation layer beneath the mold surface can be eliminated, resulting in a mold insert made of a single metal. A mold with a cavity of 25 × 50 mm² was constructed with careful design on its electrical, structural, and thermal performance. Air pockets with reinforcing ribs were embedded right beneath the mold surface for enhancing the heating performance. The resulting mold cavity can be rapidly heated from room temperature to about 240°C in 5 s with an apparent heating power of 93 W/cm². The new mold heating method was applied to thin‐wall molding and micromolding, and in all testing cases, short cycle times less than a minute were achieved. POLYM. ENG. SCI. 46:938–945, 2006. © 2006 Society of Plastics Engineers     

一种新型高光注塑模具加热方法的模拟和实验研究

采用电加热方式的高光注塑模具可以有效消除传统注塑成型过程中塑料件的熔接痕、浮纤、银纹等缺陷。然而直接将电加热棒插入模具孔中,由于间隙处的空气,大大降低了传热速度,提出一种新型电加热方法,通过在电加热棒与模具之间填充一种导热液,改变电加热棒与模具之间的接触状况,建立三维传热模型,并通过模拟和实验研究,证明了这种方法可以提高40%的加热效率,同时还能降低电加热棒内部40%的温度。     

铝合金RTM模具制备设计研究

复合材料成型工艺中树脂传递模塑(RTM)成型已在航空航天、汽车等制造领域得到广泛应用。但由于传统钢制模具质量太大,限制了大型复合材料制件采用RTM成型工艺的发展。设计研究了采用铝合金制备RTM成型模具的减轻质量效果,分析了克服铝合金材质热膨胀系数对模具形变影响的解决方案。结果表明,铝合金模具减轻质量效果尤为明显,相较钢模减轻50%;通过减小模具型腔尺寸,提高注胶和脱模温度、设置必要的保护装置等方法,可克服铝合金热膨胀系数大、硬度低等缺陷;并且其成型出的制品表面光洁,内部无分层和脱胶现象,尺寸精度达到设计要求。     

Control of H2O generated during the CO2 hardening process in a casting mold

An additive reagent was introduced into a water glass binder system for enhancing the mechanical properties and dimension stability of a casting mold, and for improving the surface quality of a cast product. Two different processes with three different additive reagents were employed to investigate the relation between fracture strength of the mold and water (H₂O) existed in the mold. In processes I and II, the mold samples were coated with a water glass binder, and then dipped into different solutions with additive reagent after and before carbon dioxide (CO₂) hardening, respectively. The fracture strength of the mold was enhanced by reducing H₂O content in the mold, achieved by a hydrolysis reaction of additive reagents. In process I, the H₂O movement was restricted in the mold by the solid phase, converted from the water glass during CO₂ hardening. When employing process II, especially in the TEOS used as additive reagent, the fracture strength was significantly increased due to the effective reduction of H₂O content in the mold and the homogeneous generation of glass phase by a sol–gel reaction of the additives.     

Effect of rapid mold surface inducting heating on the replication ability of microinjection molding light‐guided plates with V‐grooved microfeatures

This study applies a magnetic induction heating method for rapid and uniform heating of a mold surface for injection molding of 2‐inch light‐guided plates (LGPs). Mold temperature is an important process parameter that affects microinjection molding quality. This research investigates the effects of high‐mold surface temperature generated by induction heating in enhancing the replication rate of microfeatures of LGPs. This study has three stages. First, an appropriate power rate setting is determined for induction heating and injection molding process window. Second, all key parameters affecting microfeature quality are identified to determine the optimum LGP micromolding parameters using the Taguchi and ANOVA methods. Third, the quality of microfeature heights and angles are experimentally verified. Polymethyl methacrylate was molded under various injection molding conditions to replicate an electroformed nickel stamper with V‐grooves 10 μm in width and 5 μm in depth. In this investigation, injection speed was set in the conventional range. Experimental findings indicate that instead of high‐mold temperature, the combination of low mold temperature and high surface temperature obtained using induction heating improve replication quality and reduce cycle time. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

激光技术应用于模具清洗

鉴于模具清洗在轮胎，橡胶制品生产中的重要性，将激光技术与喷砂法，化学清洗剂清洗法等做了横向对比，并论述了其特性，表明激光清洗是一种高效，低成本，无污染的光电技术，比喷射法提高效率10倍以上，且对模具无损，操作安全可靠。