微米/纳米加工中的聚焦离子束技术

聚焦离子束系统正成为微细加工领域的有力工具。文章简述了聚焦离子束系统的组成和工作原理,着重介绍了该系统在离子束刻蚀、离子束辅助沉积和离子注入等微米/纳米加工领域的应用,并对聚焦离子束技术的特点及未来的发展前景进行了总结和分析。

双光子聚合加工均匀木堆结构方法的研究

由于双光子聚合所具有的纳米级加工分辨率以及真三维制造能力,被广泛应用于微米纳米制造领域。利用双光子聚合加工的三维木堆结构是实现生物支架、光子晶体、超材料等功能器件的重要途径之一。但是加工结构在经过后处理之后产生的不均匀收缩成为获得高质量木堆结构的重要阻碍,严重时会导致失去其结构的功能性。为了实现木堆结构的均匀性加工,提出一种通过降低加工结构与基底附着力的方法,来实现均匀木堆结构的加工。此外,采用Ormocomp光敏材料以及双光子聚合加工技术,对基底高附着力和低附着力的木堆结构分别进行了加工。通过对加工所得木堆结构的各层尺寸的测量,验证了所提出方法的有效性。

Deformation and fracture behavior of commercially pure titanium with gradient nano-to-micron-grained surface layer

Titanium with gradient nano-to-micron scale grains from surface to matrix was fabricated by surface mechanical grinding treatment(SMGT) at room temperature.The SMGT-treated titanium shows higher strength than that of as-received one,but moderate ductility between those of ultra-fine grained(UFG) and coarse-grained titanium.Tensile stress-strain curves of SMGT-treated titanium show double strain hardening regimes.The strain hardening rate(dσ/dε) decreases with increasing strain in tensile deformation.The high strain hardening rate at initial yielding is attributed to nano-to-micron-grained surface layer.The low strain hardening rate at large plastic strain regime primarily results from coarse-grained matrix.The SMGT-treated titanium shows a ductile fracture mode with a large number of dimples.The small size of dimples in the treated surface layer is due to the combination of the high strength and strain hardening exponent.The difference between dimple size in nano-to-micron-grained surface layer and coarse-grained matrix is discussed in terms of plastic zone size at the tip of crack in the SMGT-treated titanium.

业界动态

由北京航空制造研究所研制的双龙门四主轴数控机床近日通过中航一集团技术鉴定,可替代同类设备的进口。该机床为龙门移动结构,两个龙门架可分别独立工作;每个龙门上有两个主轴,既可同时加工两个相同的零件,也可使用其中的任意一个主轴加工;工作台面积为2500mm×2600mm;主轴转速达到10000r/min,主轴功率50kW,工作进给速度15000mm/min,可完成飞机零件的高速和高效加工。