(1. 北京航空航天大學(xué) 機(jī)械學(xué)院， 北京 100083；
2.成都飛機(jī)設(shè)計(jì)研究所， 成都 610041；
3. 成都飛機(jī)工業(yè)公司， 成都 610092)
摘 要: 為研究加工工藝對7075-T7351鋁合金飛機(jī)裝配緊固孔表面質(zhì)量的影響，通過掃描電子顯微鏡和光學(xué)顯微鏡，分別對5種不同制孔工藝所產(chǎn)生的表面微觀形貌和表層組織變化進(jìn)行了觀察和分析。結(jié)果表明，鉆擴(kuò)鉸多步慢進(jìn)給工藝和一步復(fù)合制孔工藝所加工出的表面，平整、光滑、加工缺陷少、晶格變形小、變質(zhì)層薄；而其它工藝條件下，孔表面微觀形貌復(fù)雜、加工紋路紊亂、表面缺陷多、晶格畸變大，變質(zhì)層厚，這些加工狀況，對緊固孔的裝配性能和疲勞壽命都有很大的影響。
關(guān)鍵字: 鋁合金；緊固孔；加工工藝；微觀形貌；顯微組織；加工缺陷
surface microphotograph and
microstructure of fastening holes
REN Bing-yi2， HAN Yu3
（1. Machinery College, Beijing University of
Aeronautics and Astronautics, Beijing 100083， P.R.China；
2. Chengdu Aircraft Design & Research Institute,
Chengdu 610041， P.R.China;
3. Chengdu Aircraft Industry Co. Chendu 610092， P.R.China）
Abstract: In order to study the effect of machining processes on the surface condition of fastening holes drilled on 7075 aluminum alloy for aircraft assembly, the surface microphotograph and surface layers microstructure produced by the five kinds of drilling processes were observed and analyzed by means of SEM and optical microscope. The results show that the surface microphotograph yielded in multiple-step machining with slow feeding and in one-step compound process is satisfactory, and there are fewer defects, lower deformation and thinner metamorphic layers; while that produced in other processes is quite rough, there are more defects and bigger deformation on the machined surface, and they are detrimental to assembly properties and fatigue life of fastening holes.
Key words: aluminum alloy; fastening hole; machining processes; microphotograph; microstructure; machining defect
