导管伸出长度对气雾化制备TC4粉末特性的影响

Effect of Extension Length of Catheter on Properties of TC4 Powder Prepared by Electrode Induction Melting Gas Atomization

采用电极感应熔炼气雾化法(EIGA)制备TC4钛合金粉末,模拟了雾化流场并研究了环形喷嘴中导管伸出长度对粉末形貌、粒径分布、空心球率、松装密度和流动性等特性的影响.结果表明:随着导管伸出长度的增加,负压区增大,雾化破碎更充分.当导管伸出长度为3 mm时,负压区分裂成两个独立的小负压区,制备的粉末中块状粉末和空心球增加.雾化气压为6.0 MPa、熔炼功率为60 k W、导管伸出长度为2 mm时,负压区面积大且呈倒置三角形,充满整个导管下方,液滴雾化破碎更充分;制备的粉末D(50)小于90μm,可打印粉末的收得率为51.60%;粉末松装密度为2.870 g/cm3,粉末流动性为22.23 s/50 g,空心球率≤3%,雾化制备的TC4粉末更适合激光直接沉积技术.

TC4 titanium alloy powder was prepared by electrode induction melting gas atomization （EIGA）. The atomization flow field was simulated, and the effects of extension length of the catheter on powder morphology, powder size distribution,hollow ball rate,apparent density and flow ability were investigated. The results showed that with the increase of extending length of the catheter,the negative pressure zone increases and the atomization powder is broken more fully. When the extending length is 3 mm,negative pressure zone splits into two independent small zones,and the bulk powder and hollow spheres increase. When atomization pressure,the melting power and the extending length are 6.0 MPa,60 kW and 2 mm,respectively, the negative pressure area, which is large and inverted triangular, fills the lower part of the whole catheter while the atomization is more complete. The printable powder production rate is 51.60% . Apparent density is 2.870g/cm^3 ,flow ability is 22.23s/50 g and hollow ball rate is below 3% . TC4 powder prepared by EIGA is more suitable for laser direct deposition.