试样温度对激光重熔Zr_(55)Cu_(30)Al_(10)Ni_5块体非晶合金晶化的影响  

EFFECT OF SPECIMEN TEMPERATURE ON CRYSTALLIZATION DURING LASER REMELTITNG Zr_(55)Cu_(30)Al_(10)Ni_5 BULK METALLIC GLASS

作　　者：杨高林[1] 林鑫[1] 胡桥[1] 宋梦华[1] 汪志太[1] 黄卫东[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《金属学报》2013年第8期925-931,共7页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展计划项目2011CB610402;国家高技术研究发展计划项目2013AA031103;高等学校博士学科点专项科研基金项目20116102110016;高等学校学科创新引智计划项目08040资助~~

摘　　要：分别对在液N冷却、液Ar冷却、置于室温环境和加热到473 K条件下的Zr_(55)Cu_(30)Al_(10)Ni_5非晶合金试样进行脉冲激光重熔实验,以研究试样温度对激光重熔非晶合金晶化的影响.结果显示.在采用有、无Ar气侧吹的情况下基材温度,特别是基材温度较低时,对激光重熔块体非晶合金晶化的影响规律明显不同.激光重熔实验中,无Ar气侧吹时,对在液Ar冷却和置于室温环境下的试样,激光重熔后热影响区的晶化程度类似.在液Ar冷却下的试样熔池较深.对于加热到473 K的试样,热影响区的晶化程度最为严重,且熔池最深.激光重熔实验中采用Ar气侧吹时,与室温环境的试样相比,液N冷却对于激光重熔非晶合金的晶化有明显的抑制作用.试样温度对非晶合金晶化的影响源于:一、试样本身的温度越低,热影响区的冷速越快,晶化越少;二、试样周围的气氛温度越低,激光重熔过程中,等离子体对激光的屏蔽效应也越小,实际能量输入越高,晶化越严重.有Ar气侧吹时,气氛温度为侧吹气体的温度,所以试样温度较低,晶化较少.在没有Ar气侧吹时,气氛温度接近于试样温度,上述2个因素同时作用,导致试样温度对晶化的影响规律非单调变化.Zr55Cu30Al10Ni5 bulk metallic glasses were remelted by pulsed laser at liquid N （Ar） cooling, room temperature and 473 K. The results show that the effect of specimen temperatures on the crystallization of specimens during laser remelting metallic glasses depends on the Ar blowing. If there is no Ar blowing, the crystallization of the specimen during laser remelting under liquid Ar cooling and room temperature is similar while the molten pool is deeper for liquid Ar cooling. And the specimen remelted at 473 K was most seriously crystallized with the deepest molten pool. But comparing the specimen at room temperature, the crystallization of the specimen at liquid N was suppressed during laser remelting with Ar blowing. The effects of specimen temperatures on the crystallization of metallic glasses during laser remelting are： First, the lower specimen temperature can increase the cooling rate of specimen and therefore reduce its crystallization. Secondly, the lower specimen temperature makesthe atmosphere around the specimen cooled down, reduces the shielding effect of plasma and increases the actual laser energy input into the specimen, resulting in more serious crystallization of the specimen. If there is Ar blowing, the atmosphere temperatures are similar to that at the liquid Ar cooling leading to the crystallization of the specimen to reduced. If there is no Ar blowing, the atmosphere temperature is similar to the temperature of specimen itself. In this case, the crystallization of the specimens is jointly determined by the temperature of the specimen itself and the atmosphere temperature around the specimens, which is not monotonous.

关 键 词：Zr_55Cu_30Al_10Ni_5非晶合金 试样温度 激光重熔 晶化 

分 类 号：TG24[金属学及工艺—铸造]