Untersuchungen zur Dauerfestigkeit carbonitrierter Proben aus den Einsatzstählen 18CrNiMo7‐6und 20MnCr5

The endurance limit of carbonitrided specimens of 18CrNiMo7‐6 and 20MnCr5 case hardening steels were examined under bending conditions. Four variants were manufactured differing in heat treatment and surface conditions. Besides conventional gas carburised variants, carbonitrided specimens with a low and a raised nitrogen content of 0.2 and 0.45% at the surface as well as a carbonitrided and ground variant were examined. The specimens were tested with stress ratios R = –1 and 0. Depending on the nitrogen content cyclic loading evokes compressive residual stresses at the specimens' surfaces, caused by elastic‐plastic deformation. Specimens of the ground variant show additionally a decrease of the residual austenite content when cycled. The induced compressive residual stresses are substantially responsible for high endurance limits at both stress ratios and are the key for understanding the beneficial effect of carbonitriding in this regard.     

Verbundstrangpressen von Titan‐Aluminium‐Verbindungen

Rod Extrusion of Titanium‐Aluminum Composites The combination of different metals enables the processing of materials with local optimized properties. Thus, the production of metallic composites is associated with high standards in manufacturing technologie. Focus of the following investigations is the rod extrusion process of titanium‐aluminum‐composites. Besides the mechanical properties, the formation of the bonding zone and the mechanisms of adhesion in the bonding zone were investigated. The influence of specimens’ preparation and of different coatings used improve bonding were a matter of particular interest. Whereas coatings of copper or nickel inhibit the formation of a strong bonding due to the formation of oxide layers, sealed titanium cores can reach a mechanical strength of up to 100 MPa after rod extrusion. Compared to other joining technologies, an impairment of the base metal via formation of heat affected zones, pores or grain coarsening does not occur.     

第二名悬式水园

在狭窄的长形场地上建造房子具有一定的难度,而在维也纳郊区的小斜坡上修建住宅区更是难上加难,林木繁茂的陡峭崖径把道路和建筑用地分隔开来,为设计增添了新的难题.     

旅行花园

一位"植物猎人"在维也纳第三区的一个公寓屋顶创造了他的天堂。公寓的主人同意他暂时使用屋顶,但必须保证使用期限到时,花园可以容易地进行清理。一个低造价的简易软木结构牢固地悬挂在屋顶上,这样负荷就不会直接传给下面的屋顶。冬天来临时,可以用背包把花盆里的植物搬到屋子里。背包其实是一种叫做"Buckelkraxen"的传统搬运工具,它常为奥地利阿尔卑斯山上的农夫们所使用。因此,除了少数种类外,大多数植物只有在夏天的时候,才会留在屋顶上。这个花园还有另外一个好处:园丁可以随性改变植物的摆放位置。设计者筛选植物的最重要标准是香味、气氛和     

Influence of base material,tempered condition and hardening pattern on the residual stress profile of induction hardened gears

Forschung im Ingenieurwesen - This paper discusses influences of the base material, pre-heat treatment and hardening pattern on the residual stresses of induction hardened gears with module 2 and...     

Surface Hardened Corrosion Resistant Rolling Element Bearings

Through hardening bearing steels with low alloy content are sometimes surface hardened by induction hardening to implement compressive residual stresses into the surface. This method is not regularly applied for steels with high alloy content especially not for applications in the aerospace and space industry. Here carburizing grades are used if compressive residual stresses are required. For a protection against corrosion chromium plating is applied or a through hardening chromium steel is chosen which offers no compressive residual stresses. This work deals with the evaluation of surface hardening and corrosion resistant bearing components. For this the steels AISI 440C and Cronidur30 were investigated.     

改进零件几何形状减小热处理畸变

因热处理时发生畸变,加之精度要求较高,零件热处理后通常都要进行机加工。由于通过机加工修正变形的成本太高,所以应尽可能减小零件的热处理畸变。本文研究结果证明,零件的热处理畸变与其几何形状有关。首先概述使零件几何形状成为畸变倾向重要载体的物理效应。其次,以复杂的汽车零件为例说明零件几何形状影响畸变的程度。最后介绍一种能更有效控制系统畸变的新途径。     

水路和水面

罗德诺霍夫农舍位于奥地利慕维特尔区的偏僻空地上,一对已婚夫妇周末常来此度假。翻修建筑的时候,为更好利用花园,房主和建筑师把原来倾斜的场地修成了台地。场地北边的清水混凝土墙围成一个狭窄的长形水池。房子后方天井的窗户和坐凳是用裸露的混凝土墙建成的。容易引人注意,水生植物在墙上投射下形状不同的影子。水池还具有过滤的功能。在另一头,水流淌过沙砾池底,然后进入地下泳池。一个太阳能水泵把水抽回到过滤池。泳池的四周种着黑刺李树,一棵老樱桃树为池边的观景木台提供了遮荫功能。可循     

废墟上的自然花园

新的谷仓建好之后,旧谷仓就废弃了。委托人是在斯特利亚的拉姆绍达切斯坦经营有机食物生产。他拆除了部分谷仓,并根据生态标准修建一个废墟地花园。花园坐落在海平面偏南920m的地方,能够看到陶恩山脉。设计师整合了现存建筑使用的材料、本地建筑材料和谷仓的残余墙面,重新修建了一个小庭院。墙上设置有三面木围篱,形成了休憩区和全天候沙盒。旧的肥料坑现被当作雨水蓄水池使用。干燥的泥沙石混合层成为培育毛蕊花、扁柏、大戟、百里香和常见牛舌草的温床。而在墙顶等养料相对缺乏的地方,添加的低肥泥层让锦葵、雏菊、