【摘要】 将快速凝固Mg92.5Zn6.4Y1.1合金薄带在330℃往复挤压2道次和4道次,然后再正挤压制成10mm的棒材。用OM、TEM、XRD及DTA研究了往复挤压对材料微观结构的影响。研究表明,往复挤压有利于合金薄带的焊合,获得高致密度的棒材。往复挤压2道次,棒材相组成为α-Mg和Mg3YZn6准晶(I);4道次相组成为α-Mg和原始的I相以及析出的I相和MgZn。往复挤压道次增加,I相得到细化,并有纳米相脱溶析出。更多还原

【Abstract】 Mg_92.5Zn_6.4Y_1.1 magnesium alloy bars were prepared by reciprocating extrusion（RE） and forward extrusion processes from rapidly solidified ribbons.The melt-spunning ribbons were firstly reciprocating extruded for 2 passes or 4 passes at 330℃,and then forward extruded into a rod with a diameter of 10mm.Microstructure was investigated by optical microscope（OM）,transmission electronic microscopy（TEM）,X-ray diffraction（XRD） and differential thermal analysis（DTA）.The results show that the compact bulk magnesim alloy can be prepared using the rapid solidified ribbons by RE process.The interface between ribbons is welded perfect.The microstructure of the alloy after reciprocating extrusion for 2 passes and then forward extrusion consists of α-Mg and quasicrystal Mg₃YZn₆（I）.However,the microstructure after reciprocating extrusion for 4 passes consists of α-Mg,original I-Mg₃YZn₆,nano-crystalline precipitated I and MgZn phase.Increasing RE passes,the size of original I phase decreases and the quantity of nano-precipitates precipitated from α-Mg increases.更多还原