本文選題：AZ31B鎂合金　切入點(diǎn)：雙弧焊　出處：《南昌大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：本文根據(jù)AZ31B鎂合金的特性和物性參數(shù),結(jié)合熔滴過渡理論和自由表面跟蹤算法VOF法,并利用ANSYS Workbench集成下的FLUENT軟件,結(jié)合UDF函數(shù)開展AZ31B鎂合金雙弧焊和單弧焊熔滴過渡行為的數(shù)值模擬,同時(shí)借助圖像采集系統(tǒng)和圖像處理技術(shù)進(jìn)行了實(shí)驗(yàn)驗(yàn)證,以期為AZ31B鎂合金雙弧焊焊接工藝參數(shù)的優(yōu)化提供一定的理論參考。本文首先借助軟件Workbench14.5建立了一個(gè)新穎的二維非對(duì)稱的AZ31B鎂合金雙弧焊數(shù)學(xué)模型,并用FLUENT14.5軟件借助UDF函數(shù)同時(shí)優(yōu)選VOF模型來追蹤鎂合金雙弧焊熔滴的自由表面,模擬了旁路電流為100A不變的情況下,總電流分別為170A,220A和280A時(shí)對(duì)熔滴過渡整個(gè)過程的影響。為了具體的了解總電流對(duì)熔滴偏移距離的影響,以10A的間隔模擬了總電流從170A增加到280A的熔滴的偏移距離并進(jìn)行了規(guī)律分析。為了優(yōu)化焊接參數(shù),研究了鎂合金雙弧焊接熔滴過渡的臨界電流,得到的結(jié)果大致為195A,并探討了不同的總電流條件下獲得射滴過渡(包括射流過渡)的旁路電流的范圍大小。然后,搭建了AZ31B鎂合金雙弧焊焊接實(shí)驗(yàn)系統(tǒng),拍攝得到了旁路電流為100A,總電流為170A,220A和280A時(shí)的熔滴圖像,借助Matlab軟件編寫的一系列算法,分別選取熔滴圖像的一個(gè)典型時(shí)刻進(jìn)行了處理,最終得到了熔滴的邊緣輪廓尺寸,結(jié)果顯示實(shí)驗(yàn)得到的鎂合金雙弧焊熔滴的尺寸與模擬結(jié)果之間的誤差很小,最大誤差只有6.78%。最后,在保證焊接平臺(tái)主要參數(shù)相同的情況下,對(duì)比了鎂合金雙弧焊和單弧焊的臨界電流和熔滴內(nèi)部速度場(chǎng)的不同,結(jié)果顯示鎂合金單弧焊的臨界電流為224A,與鎂合金雙弧焊相差29A;在同樣的焊接電流下鎂合金單弧焊熔滴的最大速度是1.71m/s,而添加100A旁路電流的鎂合金雙弧焊熔滴的最大速度是2.58m/s,最大速度變大。
[Abstract]:According to the properties and physical properties of AZ31B magnesium alloys, the theory of droplet transfer and the free surface tracking algorithm (VOF) are combined, and the FLUENT software integrated with ANSYS Workbench is used in this paper. The droplet transfer behavior of double arc welding and single arc welding of AZ31B magnesium alloy is simulated with UDF function, and the experimental results are verified by image acquisition system and image processing technology. In order to provide some theoretical reference for optimization of welding process parameters of AZ31B magnesium alloy double arc welding, a novel two-dimension asymmetric mathematical model of double arc welding for AZ31B magnesium alloy is established with the help of software Workbench14.5. The free surface of droplet in double arc welding of magnesium alloy is tracked by FLUENT14.5 software with the help of UDF function and the VOF model is selected at the same time, and the bypass current is 100 A invariant. The effect of total current of 170An 220A and 280A on the whole process of droplet transfer. The offset distance of droplet increasing from 170A to 280A was simulated at 10A intervals and the regularity was analyzed. In order to optimize welding parameters, the critical current of droplet transfer in magnesium alloy double-arc welding was studied. The results obtained are approximately 195A, and the range of bypass current of droplet transfer (including jet transfer) obtained under different total current conditions is discussed. Then, a double-arc welding experiment system for AZ31B magnesium alloy is built. The droplet images with 100A bypass current, 170A 220A and 280A total current were recorded. A typical time of the droplet image was selected and processed by a series of algorithms written by Matlab software. Finally, the size of the edge profile of the droplet was obtained. The results show that the error between the size of droplet and the simulation results is very small, and the maximum error is only 6.78. Finally, when the main parameters of the welding platform are the same, The difference of critical current and droplet velocity field between double arc welding and single arc welding of magnesium alloy is compared. The results show that the critical current of single arc welding of magnesium alloy is 224A, which is 29 A different from that of double arc welding of magnesium alloy, and the maximum velocity of droplet of single arc welding of magnesium alloy is 1.71 m / s under the same welding current, while that of double-arc welding droplet of magnesium alloy with 100A bypass current is the highest. The big speed is 2.58 m / s, and the maximum speed gets bigger.
【學(xué)位授予單位】：南昌大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TG457.19

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 宋加強(qiáng);肖s，

本文編號(hào)：1576757