高速电弧喷涂粒子速度和雾化特性研究

PARTICLE VELOCITY AND ATOMIZING CHARACTERISTIC IN HIGH VELOCITY ARC SPRAY PROCESS

对比研究了高速电弧喷涂和普通电弧喷涂ＡＩ和３Ｃｒ１３的粒子速度和雾化特性，用Ｐｉｔｏｔ管总压法。双转盘法和扫描电镜、图象分析仪分别测定了喷枪出口雾化气流速度和粒子速度的轴向分布，以及不同工艺条件下雾化粒子的粒度分布。用ＰｅａｒｓｏｎＸ２分布拟合检验法对粒子的粒度分布进行统计分布检验。结果表明，高速电弧喷涂ＡＩ和３Ｃｒ１３粒子的平均飞行速度为３４２ｍ／ｓ和３８８ｍ／ｓ；雾化粒子平均粒度分别为普通电弧喷涂的１／３和１／８；雾化气流轴向速度在主要雾化区间（ｄ＜１００ｍｍ）为７００－５５０ｍ／ｓ；高速电弧喷涂和普通电弧喷涂川粒子的粒度具有相同的分布规律，而高速电弧喷涂３Ｃｒ１３粒子的粒度却具有不同的分布规律。探讨了高速电弧喷涂雾化机理和影响粒子速度的因素。

The particles velocity and atomizing characteristics ofdroplets in high velocity are spray (HVAS) and regular arc sprayprocesses are inveshgated respectively. Both atomizing gas flowvelocity and particle flying velocity are measured by a dual rotatingdisk techniqUe and pilot tube method respechvely. The particle sizedistribuhon under various are sprayed pubesses is inveshgated byuse of a sccing elecbon microscope and an image analyzer.Stahstical tests for their phocle size distributions are cabed outaccording to Pearson X2 distribution test method. Results show thatthe axial gas now velocity of HVAS fluctuated ranging horn 550m/stO 700 m/s at the primal atomizing zone, i. e. spray distance within100 mm. The average particle velocihes of high velocity arc sprayedaluminum and chmmium alloy steel reached 342 m/s and 388m/srespectively, which are in excess of the local velocity of sound. BothHVAS and regular are sprayed alednum's palticle size followedPoisson distribuhon. However high velocity arc sprayed chromiumsteel had dtherent pwhcle size distribution horn that of regtilar are.The influence factors on palticle velocity and atomiaing mechbosmof HVAS process are also discussed on the basis of caveexperimental results and analyzing of gaS flow velocity field.