CAJ | 학술논문

通过 ANSYS 有限元数值模拟和试验相结合，研究了超声波对BT20钛合金激光沉积修复过程的作用。结果表明，超声波振幅为0.2~0.55μm 时，能得到成形质量较好的修复层；当超声波振幅为0.4μm 时，超声波对熔池的作用主要表现为超声的机械作用和热作用，而不是超声空化效应；超声的机械作用使得组织的气孔率降低，但是其机械作用不足以克服修复层晶粒外延生长的驱动力，没能阻止柱状晶沿沉积方向的生长；超声的机械作用将晶粒片层组织中的板条打断，而热作用使得熔池凝固速度降低，从而使板条变短变粗。
통과 ANSYS 유한원수치모의화시험상결합，연구료초성파대BT20태합금격광침적수복과정적작용。결과표명，초성파진폭위0.2~0.55μm 시，능득도성형질량교호적수복층；당초성파진폭위0.4μm 시，초성파대용지적작용주요표현위초성적궤계작용화열작용，이불시초성공화효응；초성적궤계작용사득조직적기공솔강저，단시기궤계작용불족이극복수복층정립외연생장적구동력，몰능조지주상정연침적방향적생장；초성적궤계작용장정립편층조직중적판조타단，이열작용사득용지응고속도강저，종이사판조변단변조。
The effect of ultrasonic on laser deposition process in repaired components of BT20 titanium alloy was investigated by using finite element simulation and experimental test. The results show that when ultrasonic amplitude was 0.2 -0.55 μm, the forming quality of repaired layers was better; When ultrasonic amplitude was 0.4 μm, the effect of ultrasonic on molten pool was mainly about mechanical effect and thermal effect, not ultrasonic cavitation effect. The mechanical effect declines the porosity rate of organization, but the mechanical force was less than the epitaxial growth driving force of crystalline grain in repaired layers so that the growth of -columnar grain along the direction of deposition could not be blocked; The mechanical effect breaks the -lath of lamellar microstructure and the thermal effect makes the solidification speed slow, as a result, the -lath was becoming short and thick.