热处理对压铸镁合金化学镀层组织和性能的影响  

Effect of heat treatment on microstructure and properties of electroless Ni-P deposits on AZ91D magnesium alloy

作　　者：张金旺[1,2] 侯利锋[1,2] 许并社[1,2] 

机构地区：[1]太原理工大学新材料界面科学与工程省部共建教育部重点实验室,山西太原030024 [2]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《材料热处理学报》2010年第2期137-140,共4页Transactions of Materials and Heat Treatment

基　　金：山西省青年学术带头人项目;山西省青年科技基金(20041023)

摘　　要：采用化学镀方法在AZ91D压铸镁合金表面获得N i-P镀层,研究了不同热处理温度对镀层的组织和性能的影响。结果表明:镍层中P含量为6.22 wt%,镀层组织为非晶+少量纳米晶组织。随热处理温度升高原始镀层中的非晶组织中先形成镍纳米晶,然后纳米晶镍伴随晶化过程进行迅速长大,并在镍基体上析出N i12P5和N i3P相。镀层与基体的结合强度在350℃附近达最大结合强度为3.7 MPa,镀层硬度在400℃附近达最大值为825 HV;盐雾腐蚀实验表明镀层耐腐蚀性能良好,连续盐雾8 h未出现腐蚀斑点。经过不同的热处理,镀层的耐蚀性随着热处理温度的提高而下降。The Ni-P plating was prepared on AZ91D magnesium alloy by electroless deposit.The effect of heat treatment temperatures on the microstructure and property of the Ni-P deposit was investigated by means of SEM,XRD,TEM,microhardness test and spray corrosion tests.The results show that the plating with 6.22 wt% phosphorus consists of amorphous and nanocrystalline microstructure.Nanocrystalline nickel forms firstly in the amorphous during annealing.The grain sizes of the nickel grow rapidly during crystallization.Ni3P and a little of Ni12P5 phases form in nickel matrix of the deposited coating after annealing.The maximium adhesion strength of 3.7 MPa is obtained for the deposited coating annealed at 350 ℃.The maximum hardness of the coating is 825 HV when annealing the temperature reachs 400 ℃.The salt spraying test shows that good corrosion resistance of the plating is observed,however,the corrosion resistance gradually declines with increasing annealing temperature.

关 键 词：镁合金 化学镀 组织 性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG174.4[金属学及工艺—金属材料]