表面技术
錶麵技術
표면기술
SURFACE TECHNOLOGY
2015年
6期
11-16
,共6页
张晓东%揭晓华%罗松%郑琼彬
張曉東%揭曉華%囉鬆%鄭瓊彬
장효동%게효화%라송%정경빈
激光熔覆%WC/Co-Cr复合涂层%显微组织%元素分布
激光鎔覆%WC/Co-Cr複閤塗層%顯微組織%元素分佈
격광용복%WC/Co-Cr복합도층%현미조직%원소분포
laser cladding%WC/Co-Cr composite coating%microstructure%distribution of chemical element
目的：优化复合涂层的熔覆工艺参数,获得综合性能优异的WC/Co-Cr复合涂层。揭示复合涂层的相结构、组织构成及界面特性。方法采用YAG固体激光器在45钢上熔覆WC/Co-Cr复合涂层,以电流、频率、脉宽、扫描速度作为变量,设计四因素三水平正交试验,对熔覆效果进行评分,获得最佳参数组合。通过XRD,XRF,OM,EMPA等分析手段对复合涂层进行表征。结果电流对熔覆效果的影响最显著,其次为频率,再次之为激光扫描速度,脉宽的影响显著性最小。随WC含量增加,激光脉宽应增加,而激光扫描速度应该适当减小。复合涂层的显微组织形貌主要为固溶体上分布着共晶组织以及金属间化合物、碳化物,还有由成分过冷导致的胞状组织。复合涂层的物相组成包括CrCo,WC,Cr7 C3,Cr3 C2等。结论采用WC质量分数10%的熔覆粉末,最佳熔覆工艺组合为：电流380 A,频率40 Hz,脉宽1 ms,扫描速度8 mm/s。采用WC质量分数20%的熔覆粉末,最佳熔覆工艺组合为：电流380 A,频率40 Hz,脉宽1.5 ms,扫描速度6 mm/s。复合涂层与混合粉末相比,相组成发生了变化,有金属间化合物、碳化物等强化相产生,且元素在界面的分布呈现过渡式变化,这对涂层的综合性能有利。
目的：優化複閤塗層的鎔覆工藝參數,穫得綜閤性能優異的WC/Co-Cr複閤塗層。揭示複閤塗層的相結構、組織構成及界麵特性。方法採用YAG固體激光器在45鋼上鎔覆WC/Co-Cr複閤塗層,以電流、頻率、脈寬、掃描速度作為變量,設計四因素三水平正交試驗,對鎔覆效果進行評分,穫得最佳參數組閤。通過XRD,XRF,OM,EMPA等分析手段對複閤塗層進行錶徵。結果電流對鎔覆效果的影響最顯著,其次為頻率,再次之為激光掃描速度,脈寬的影響顯著性最小。隨WC含量增加,激光脈寬應增加,而激光掃描速度應該適噹減小。複閤塗層的顯微組織形貌主要為固溶體上分佈著共晶組織以及金屬間化閤物、碳化物,還有由成分過冷導緻的胞狀組織。複閤塗層的物相組成包括CrCo,WC,Cr7 C3,Cr3 C2等。結論採用WC質量分數10%的鎔覆粉末,最佳鎔覆工藝組閤為：電流380 A,頻率40 Hz,脈寬1 ms,掃描速度8 mm/s。採用WC質量分數20%的鎔覆粉末,最佳鎔覆工藝組閤為：電流380 A,頻率40 Hz,脈寬1.5 ms,掃描速度6 mm/s。複閤塗層與混閤粉末相比,相組成髮生瞭變化,有金屬間化閤物、碳化物等彊化相產生,且元素在界麵的分佈呈現過渡式變化,這對塗層的綜閤性能有利。
목적：우화복합도층적용복공예삼수,획득종합성능우이적WC/Co-Cr복합도층。게시복합도층적상결구、조직구성급계면특성。방법채용YAG고체격광기재45강상용복WC/Co-Cr복합도층,이전류、빈솔、맥관、소묘속도작위변량,설계사인소삼수평정교시험,대용복효과진행평분,획득최가삼수조합。통과XRD,XRF,OM,EMPA등분석수단대복합도층진행표정。결과전류대용복효과적영향최현저,기차위빈솔,재차지위격광소묘속도,맥관적영향현저성최소。수WC함량증가,격광맥관응증가,이격광소묘속도응해괄당감소。복합도층적현미조직형모주요위고용체상분포착공정조직이급금속간화합물、탄화물,환유유성분과랭도치적포상조직。복합도층적물상조성포괄CrCo,WC,Cr7 C3,Cr3 C2등。결론채용WC질량분수10%적용복분말,최가용복공예조합위：전류380 A,빈솔40 Hz,맥관1 ms,소묘속도8 mm/s。채용WC질량분수20%적용복분말,최가용복공예조합위：전류380 A,빈솔40 Hz,맥관1.5 ms,소묘속도6 mm/s。복합도층여혼합분말상비,상조성발생료변화,유금속간화합물、탄화물등강화상산생,차원소재계면적분포정현과도식변화,저대도층적종합성능유리。
ABSTRACT:Objective To optimize the laser cladding operation of excellent WC/Co-Cr composite coating, and to figure out the phase, microstructure and distribution of chemical elements of composite coating. Methods YAG Laser was utilized to carry out WC/Co-Cr composite coating on 45 carbon steel. Orthogonal experiments were performed which contains four factors at three differ-ent levels. Four factors were current, frequency, pulse width and scanning speed. Several characterization techniques, such as XRD, XRF, OM and EMPA, were employed to characterize the phases, structure and interface of WC/Co-Cr Composite coating. Results The influence of the Electric current to the cladding effect was the most significant, followed with the frequency, the laser scanning speed, and then the Pulse-width. Laser pulse width should be increased, conversely, laser scanning speed should be re-duced with the increase of WC content. The microstructure of composite coating are eutectic, carbide and intermetallic distributing on solid solution. In addition, cell structure caused by composition undercooling was observed on the micro-graph. The phases of coating are CrCo, WC, Cr7 C3 and Cr3 C2 . Conclusion Current is the main influence factor for Laser cladding. Two optimum tech-nological parameters combinations are respectively 380 A, 40 Hz, 1 ms, 8 mm/s for coating which contains 10wt%WC, and 380 A, 40 Hz, 1. 5 ms, 6 mm/s for coating which contains 20wt%WC. Several new phases were observed after laser cladding, such as carbide and intermetallic. The distribution of chemical element along with the cross section are transitional. Our results suggest there is a transition region between the coating and substrate.
