(1. 華南理工大學(xué) 機(jī)械與汽車工程學(xué)院，廣州 510640；
2. 廣州有色金屬研究院，廣州 510650)
摘 要: 為了快速直接制造結(jié)構(gòu)復(fù)雜、性能優(yōu)異的個(gè)性化醫(yī)用金屬植入體，保證成型件具有良好的組織結(jié)構(gòu)和生物特性，通過激光選區(qū)熔化技術(shù)對滿足ASTMF75要求的CoCrMo合金進(jìn)行增材制造。通過正交試驗(yàn)和響應(yīng)曲面設(shè)計(jì)方法優(yōu)化致密度工藝參數(shù)，觀察成型件的微觀組織，分析試樣在模擬人體體液環(huán)境中的耐腐蝕性，并探究熱處理工藝對其耐腐蝕性的影響。結(jié)果表明：在激光功率168 W、掃描間距0.06 mm、掃描速度550 mm/s時(shí)，成型零件的致密度可以達(dá)到98.58%，且微觀組織均勻。電化學(xué)實(shí)驗(yàn)結(jié)果顯示試樣的腐蝕電流密度值約為40 μA/cm2，經(jīng)過退火熱處理后，腐蝕電流密度僅為20.86 μA/cm2，其耐腐蝕性能優(yōu)于鑄造CoCrMo合金的，這為選區(qū)激光熔化成型CoCrMo合金在醫(yī)學(xué)植入體方面的應(yīng)用提供了依據(jù)。
關(guān)鍵字: CoCrMo合金；激光選區(qū)熔化；致密度；響應(yīng)曲面；耐腐蝕性；熱處理
（1. School of Mechanical and Automotive Engineering, South China University of Technology,
Guangzhou 510640, China;
2. Guangzhou Research Institute of Nonferrous Metals, Guangzhou 510650, China）
Abstract:In order to directly fabricate personalized medical metallic implants with complex structure and excellent properties and ensure the parts have good microstructure and biological characteristics, the CoCrMo alloy satisfying the requirement of ASTMF75 is fabricated by selective laser melting (SLM) technology. The parameters of relative density were optimized by orthogonal experiment and response surface design. The microstructure of the specimens was observed, and the corrosion characteristic of the samples in simulated body fluid environment was analyzed while the influence of heat treatment process on the corrosion resistance was explored. The results show when the laser power is 168 W, the scanning space is 0.06 mm and the scanning speed is 550 mm/s, the relative density of CoCrMo alloy samples fabricated by SLM can reach 98.58%, and the microstructure is homogeneous. The electrochemical experimental results demonstrate that the corrosion current density value of the sample is about 40 μA/cm2, and becomes only 20.86 μA/cm2 after annealing heat treatment. The corrosion resistance is better than that of fabricated by casting methods, which provides the basis for the application of CoCrMo alloy directly fabricated by SLM in medical implants.
Key words: CoCrMo alloy; selective laser melting; relative density; response surface; corrosion characteristic; heat treatment
