文章信息/Info

Title:

Simulation on the Rapid Solidification Process of Titanium Alloy Powders Prepared by Gas Atomization

文章編號(hào):

1674-3962(2021)11-0894-06

作者:

王利卿; 趙少陽; 談萍; 殷京甌; 李增峰; 沈壘

（西北有色金屬研究院 金屬多孔材料國家重點(diǎn)實(shí)驗(yàn)室，陜西 西安 710016）

Author(s):

WANG Liqing;  ZHAO Shaoyang;  TAN Ping;  YIN Jingou;  LI Zengfeng;  SHEN Lei

(State Key Laboratory of Porous Metal Materials, Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China)

關(guān)鍵詞:

氣霧化; 鈦合金; 球形粉末; 快速凝固; 流體力學(xué)

Keywords:

gas atomization;  titanium alloy;  spherical powders;  rapid solidification;  fluid dynamic

分類號(hào):

G146.2

DOI:

10.7502/j.issn.1674-3962.202009022

文獻(xiàn)標(biāo)志碼:

A

摘要:

氣霧化制粉技術(shù)是目前制備球形鈦合金粉末應(yīng)用最廣泛、最成熟的技術(shù)之一。基于流體力學(xué)模擬方法，粉末破碎機(jī)理研究獲得了很大進(jìn)步。而在氣霧化制粉過程中，金屬熔滴在高速氣流的強(qiáng)制冷卻作用下快速凝固形成粉末顆粒，很大程度上決定了粉末的微觀組織及性能。針對(duì)熔滴快速凝固過程，利用Fluent軟件模擬霧化氣體與合金熔滴之間的熱量傳輸過程，揭示熔滴快速凝固過程中固液相分布規(guī)律。結(jié)果顯示，隨著霧化壓力增加，氣流匯聚中心軸線上的最大氣流速率由190增加到290 m·s-1；在不同氣流速率的作用下，鈦合金熔滴凝固速率達(dá)到103~104 K·s-1；隨著熔滴粒徑減小或者氣流速率增加，熔滴凝固速率均逐漸增加。熔滴凝固過程中，氣流流動(dòng)導(dǎo)致熔滴表面?zhèn)鳠岵痪鶆颍�造成熔滴�?nèi)部出現(xiàn)不均勻凝固過程。

Abstract:

Gas atomization is the most widely used and mature technology to prepare spherical titanium alloy powders. The formation process of the powders, especially the breakup mechanism, has been revealed by the computational fluid dynamics approach. But for the gas atomization process, metal droplets rapidly solidify and form powders under the forced cooling of high-speed gas flow, which primarily determined the microstructure and properties of the powders. In this study, Fluent software was used to simulate the heat transfer process between the gas flow and the droplet to reveal the rapid solidification process. The results indicated that, for the present atomizer, with the increase of atomization pressure, the maximum gas velocity on the central axis increased from 190 to 290 m·s-1. The solidification rate of titanium alloy droplet reached 103~104 K·s-1 under the action of different gas velocity. With the decrease of droplet size or the increase of gas velocity, the solidification rate increases gradually. In the rapid solidification process, the gas flow leads to the uneven heat transfer on the surface of the droplet, resulting in the heterogeneous solidification process inside the droplet.