硬脆材料加工用微乳化切削液的研究及应用

硬脆材料加工用微乳化切削液应用于精密陶瓷、光学玻璃、蓝宝石等硬脆材料的加工过程,由表面活性剂、基础油、润滑添加剂、极压剂、防锈剂和水等成份组成,配合金刚石工具应用于硬脆材料的切割、铣磨、精磨、磨边、倒角等加工过程,具有良好的润滑、极压、冷却、清洗和防锈等性能。     

金刚石线锯切割设备现状分析

随着光伏、半导体等高精端产业的发展,硬脆性材料,如晶体硅、蓝宝石、特种陶瓷等材料的切割加工显得尤为重要。近年来,世界各国大力投入研究开发,新工艺,新设备不断涌现。金刚石线锯切割成为研究和发展的主流趋势,文章介绍国外切割设备研究的最新进展以及国内发展状况,分析其性能优势,展望金刚石线切割设备应用前景。     

中国超硬材料制品技术现状与发展

我国超硬材料制品技术的发展已经经历了机械加工、地质勘探、石材加工等几个明显的大发展阶段.跨入新世纪以来,随着技术的进步、国家发展战略的调整及环保理念的普及,行业迎来了新的机会,进入了全面开花的新阶段.一方面,传统产品的质量和技术含量仍然在稳定地提高,市场持续扩大;另一方面,在新产品、新技术研发方面不断取得突破,新一代高附加值的制品被不断地开发出来.文章在回顾过去所取得的进步和成绩的同时,更多地研讨“十二五”规划中,在国家战略性高新产业发展的机遇期,在提高现有产品质量的基础上,如何向更高端精密的超硬材料制品方向发展.对其中用于单晶硅、多晶硅、功能陶瓷等贵重硬脆材料切割、磨削加工的高新超硬材料制品,做了比较详细的论述和展望,对超硬材料制品技术的发展提出了自己的看法.     

电镀金刚石线锯研究进展

电镀金刚石线锯在单晶硅片和蓝宝石等贵重硬脆材料的切割加工领域广泛应用,其切割效率高、损耗小。文章就电镀金刚石线锯的研究现状及发展趋势做了分析与阐述。电镀金刚石线锯的生产效率过低,应通过调整镀液、制备工艺等途径提高线锯生产效率;目前市场上的金刚石线锯切削性能还不够理想,应通过控制切削参数及磨料分布进行改善;最终实现高性能金刚石线锯快速电镀制备工艺的完善。     

可高速切断任何难加工材料和超硬材料的切断加工机研制成功

日本应用磁气研究所采用其公司独创的电解放电复合磨削加工方法(MEEC加工),研制出能够对磁性材料进行切断、切槽和平面研磨的切断加工机(MEEC 全自动微型切断机)。现已由代销商店正式出售。该机具有1/1000毫米的高精度加工能力,可高速切断任何难加工材料和超硬材料。适用于切割非晶体材料、陶瓷和新型铁硅铝磁合金等新材料,效果良好。尤其是加工电气材料时,最大的优点是不会降低或破坏其特性和功能,而且在该机的电     

工业金刚石持续高景气 培育钻石成未来新风口

超硬材料主要用于金属及合金材料、高硬脆材料、复合材料、软韧材料以及难加工材料的加工,同时作为一种重要的功能材料,可应用于电子电器、装备制造、航空航天、国防军工、医疗检测和治疗等高科技领域。目前常见的超硬材料有天然金刚石、人造金刚石、立方氮化硼等。全球工业用超硬材料主要为工业金刚石,其中超过90%为人造金刚石。     

超硬工具的时代来了

目前，世界上已知材料中金刚石及立方氮化硼是最硬的两种材料。由于它们硬度大大超出其它材料数倍，因而人们将这两种材料称为超硬材料。金刚石由于性能优越，应用不断地扩大，已从金属加工发展到了光学玻璃加工、石材加工、陶瓷加工、硬脆材料加工等传统加工难进行加工的领域，对各种工业发展将起到巨大的推动作用，金刚石工具前景十分广阔。     

水射流导向激光技术

激光最常应用的技术之一是激光加工.对于熔点高、硬度大、性质脆的材料采用激光加工有其优越性.它是利用能量密度极高的激光束照射到工件上,使材料瞬间熔化或汽化,同时在冲击波的作用下将熔融材料微粒吹开,从而对工件进行切割、钻孔等加工作业.这种传统的激光加工技术因为有对工件的切割面周围产生热损伤及与熔屑微粒沾污问题,所以在坚硬材料和金属薄片精密微加工中的应用受到限制.     

高线速下碳化硅单晶的快速平坦化切割

碳化硅单晶材料硬度很高,用传统的切片方式难以加工、效率低下,多线切割是加工硬脆材料的有效方式,文章通过使用电镀金刚石线多线切割设备,进行了高线速度条件下快速碳化硅单晶平坦化切片实验。为提高碳化硅切割效率,通过提高金刚石线速度,成功实现了用5.5小时进行4英寸碳化硅晶锭的切割,并将切割6英寸晶锭时间缩短至12小时左右。同时,为减小切割片翘曲度,进行了4英寸和6英寸碳化硅晶锭的切割试验,证明切割线速度直接影响切割片的翘曲度:随着线速度增大,晶片翘曲度减小。最后,研究了线速度和金刚石浓度对切割片表面的影响,发现提高线速度和使用高金刚石浓度的金刚石线都可使切割导致的损伤层减小。     

碳纤维增强复合材料加工方法研究

碳纤维增强复合材料是一种新型的复合材料,具有特殊的材料性能和复杂的组成结构,属于难加工材料,如果加工方式选择不当,容易造成工件尺寸精度和表面质量不合格.因此,采用光纤激光切割、机械加工及数控超高压水切割三种加工方式分别对碳纤维增强复合材料进行试验研究,最终得出数控超高压水切割加工能够达到碳纤维增强复合材料工件加工尺寸精...     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。