Plasma Nitriding of Spray‐Formed Aluminum Alloys
Plasma Nitriding of Spray‐Formed Aluminum Alloys
复制标题
喷射成形铝合金的等离子渗氮
DOI：
10.1002/adem.201200257
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发表时间：
2013
影响因子：
3.6
通讯作者：
R. Zenker
中科院分区：
文献类型：
--
作者：
A. Buchwalder;A. Dalke;H. Spies;R. Zenker
机动车辆中的发动机部件经受永久增加的机械、摩擦和腐蚀应力。轻量化结构的成功实施，例如，分别用于阀或活塞，需要使用表现出低比重以及足够热稳定性的材料。因此，考虑使用喷射成形铝合金。特定的生产工艺使得能够在宽范围内设计与负载相关的化学组成，更高含量的Fe或Ni分别用于改善耐热性和更高的应用温度。由于它们通常具有15 - 35wt%的高Si含量，喷射成形的Al合金具有比常规Al合金更高的耐磨性水平。然而，如果在高负荷应用中使用喷射成形的Al材料，则必须考虑额外的表面保护处理。在现代工业中，热处理和/或热化学处理是广泛接受的工艺，以在一个部件内结合联合收割机不同的本体和表面性质。应该注意的是，与铁合金相比，关于铝合金的有用技术的范围显然是有限的，这是由于不同的现有材料特定机制来提高表面硬度。铸造铝合金和变形铝合金的离子渗氮已取得了相当大的进展。这些研究显示了元素镁的本质影响，其改善氮化物层的生长，以及硅，其阻碍AlN层的生长。与现有的关于AlSi合金氮化行为的文献信息不同，以前的研究已经证明，喷射成形的Al合金具有高达17-25 ma%的高硅含量是良好的可氮化性。良好的氮化行为可以追溯到特定的专门的硅（Sip）作为细分散的小颗粒（2-5 mm）在喷射成形的Al基体内的初级沉淀。结果表明，AlN的形成可以改善铝的表面性能，因为它具有高硬度（>1200 HV 0.05）和耐磨性以及
Engine components in motor vehicles are subjected to permanently increasing mechanical, tribological, and corrosive stresses. The successful implementation of lightweight constructions, e.g., for valves or pistons, respectively, requires the use of materials exhibiting low specific density as well as sufficient thermal stability. Therefore, the use of sprayformed aluminum alloys is considered. The specific production process enables design of a load-related chemical composition in a wide range, e.g., high contents of Fe or Ni for improved heat resistance and higher application temperatures, respectively. Due to their typically high Si contents of between 15 and 35 wt% spray-formed Al alloys have a higher level of wear resistance than conventional Al alloys. However, if spray-formed Al materials are used in high-load applications, additional surface protection treatments have to be taken into consideration. In modern industry thermal and/or thermochemical treatments are widely accepted processes to combine different bulk and surface properties within one component. It should be noted that the range of useful technologies concerning Al alloys when compared to Fe alloys is clearly limited due to the different existing material-specific mechanisms to enhance the surface hardness. Considerable progress has been achieved in the field of plasma nitriding of cast and wrought Al alloys. These investigations showed the essential influence of the element Magnesium, which improves the growth of the nitride layer, and silicon, which impedes the growth of the AlN layer. Differing from the available literature information on the nitriding behavior of AlSi alloys previous investigations have already proved that spray-formed Al alloys with high silicon contents up to 17–25 ma% are well nitridable. The good nitriding behavior can be traced back to the specific exclusively primary precipitation of silicon (Sip) as finely dispersed small particles (2–5 mm) within the sprayformed Al matrix. It has been shown that the surface properties of aluminum can be improved by the formation of AlN because it exhibits high hardness (>1200 HV0.05) and wear resistance as well as