负热膨胀材料及其在激光熔覆中的应用  

Negative thermal expansion materials and their applications in laser cladding

作　　者：王刚 雍耀维[1] 王乾 陈小红 WANG Gang;YONG Yao-wei;WANG Qian;CHEN Xiao-hong(School of Mechanical Engineering,Ningxia University,Yinchuan 750021,China;School of Mechanical Engineering,Tianjin University of Technology and Education,Tianjin 300222,China;Jiaokou Branch,Lvliang College,Lvliang 032400,China)

机构地区：[1]宁夏大学机械工程学院,宁夏银川750021 [2]天津职业技术师范大学机械工程学院,天津300222 [3]吕梁学院交口分院,山西吕梁032400

出　　处：《激光与红外》2023年第5期677-684,共8页Laser & Infrared

基　　金：宁夏重点研发计划(引才专项)项目(No.2020BEB04030)资助。

摘　　要：激光熔覆是一种典型的表面改性技术,已得到了广泛的应用。在激光熔覆快速冷凝过程中容易产生热应力,进而产生变形,严重时会产生裂纹、失效等缺陷。负膨胀材料是指在一定温度范围内材料体积出现热缩冷涨行为的材料,和热胀冷缩材料正好相反,负膨胀材料的发现为解决材料在受热时出现膨胀变形和失效提供了处理方法。正确的使用负膨胀材料可以抑制激光熔覆加工中的裂纹和热应力集中等缺陷,提高熔覆层的机械性能,产生热膨胀可控的材料甚至零膨胀材料。本文分析了激光熔覆中裂纹产生的机理,对负膨胀材料的种类及负膨胀的原理进行了总结,对每种负膨胀材料产生负膨胀行为的条件进行了对比和分析,负膨胀材料的膨胀系数和产生负膨胀行为的温度区间会影响在激光熔覆过程中的使用。重点对国内外已经实验验证的负膨胀材料在激光熔覆中的应用进行了总结概括,提出负膨胀材料在激光熔覆中存在的一些普遍规律,以及现阶段负膨胀材料在激光熔覆应用中的不足,对负膨胀材料在激光熔覆中的应用进行概括和展望。Laser cladding is a typical surface modification technique that has been widely used.The rapid condensation process of laser cladding is prone to thermal stresses and consequent deformations,which can lead to serious defects such as cracks and failures.Negative expansion material refers to the material that exhibit heat-shrinking and cold-rising behavior in the volume of the material within a certain temperature range.Contrary to thermal expansion and contraction materials,the discovery of negative expansion material provides a treatment method to the deformation and failure of material that expand when exposed to heat.The correct use of negative expansion materials can suppress defects such as cracks and thermal stress concentration in laser cladding process,improve the mechanical properties of the cladding layer and produce materials with controllable thermal expansion or even zero expansion materials.In this paper,the mechanism of crack generation in laser cladding is analyzed,the types of negative expansion materials and the principle of negative expansion are summarized,and the conditions for negative expansion behavior of each negative expansion material are compared and analyzed,and the expansion coefficient of negative expansion materials and the temperature range that produce negative expansion behavior affect the use in the laser cladding process.The applications of negative expansion materials in laser cladding that have been experimentally verified at home and abroad are summarized and outlined,some general rules of negative expansion materials in laser cladding,as well as the shortcomings of negative expansion materials in laser cladding applications at this stage are proposed,and an overview and outlook on the use of negative expansion materials in laser cladding are presented.

关 键 词：激光熔覆 热胀冷缩 缺陷 负膨胀材料 裂纹抑制 

分 类 号：TN249[电子电信—物理电子学]