(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 利用激光束掃描金屬粉末過(guò)程中的球化效應(yīng)，探索了將異形黃銅粉轉(zhuǎn)化為球形粉末的可行途徑，研究了激光功率、掃描速度對(duì)粉末顆粒球化過(guò)程的影響，并對(duì)粉末顆粒的熔化、熔滴鋪展和收縮球化過(guò)程進(jìn)行了理論分析。結(jié)果表明：粉末的球化、鋪展和收縮過(guò)程非常短暫，分別在10−5、10−2和10−4 s以內(nèi)完成，且粒度越細(xì)，歷時(shí)越短。熔滴鋪展與收縮的協(xié)調(diào)是成球的關(guān)鍵，理想的球化效果只有在激光工藝參數(shù)、粉末物性和球化環(huán)境相互協(xié)同的條件下才能實(shí)現(xiàn)，對(duì)于粒度小于50 μm的異形黃銅粉，在激光功率為500 W、掃描速度為30 mm/s時(shí)轉(zhuǎn)化為表面平滑、高球形度的黃銅粉。
關(guān)鍵字: 黃銅粉末；激光；球化效應(yīng)
CHEN Xin, HUANG Jin-song
（Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:The irregular particle may melt rapidly and then retract to spherical particle through balling effect by laser beam scanning. The approach of transferring irregular brass powder into spherical powder by laser scanning was explored. The influences of laser power and scanning speed of laser beam and the process of melting, spreading and retracting were analyzed theoretically. The results show that the times of melting, spreading and retracting are very short, which are about 10−5, 10−2 and 10−4 s. And the smaller the particle size is, the quicker the process is. When the laser power was 500 W and scanning speed was 30 mm/s, the spherical brass powder is made from irregular brass powder with diameter of 50 μm. The interval between spreading and retracting is crucial to the balling process, and the ideal balling effect occurs only under the condition of good combination of process parameters, powder feature and environment.
Key words: brass powder; laser; balling effect
