| 引用本文: | 陈昊鑫,张桂香,刘宁,姜林志,朱培鑫,杜嘉静.选区激光熔化TC4钛合金表面磁力光整加工的表面质量[J].中国表面工程,2023,36(1):106~115 |
| CHEN Haoxin,ZHANG Guixiang,LIU Ning,JIANG Linzhi,ZHU Peixin,DU Jiajing.Surface Quality of SLM TC4 Titanium Alloy Surface by MAF[J].China Surface Engineering,2023,36(1):106~115 |
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| 摘要: |
| 为了研究磁力光整加工工艺对 SLM 制备的 TC4 钛合金表面完整性的影响，采用响应曲面法对钛合金试样进行三因素三水平的响应曲面分析试验。首先使用数控成形磨床对 SLM 制备的 TC4 钛合金试样进行磨削加工，磨削加工将钛合金试样表面粗糙度从 6 μm(SLM 成形后)下降到约 0.6 μm，使带有球状体和凹坑等缺陷的粗糙表面演化为有划痕和孔隙的细表面。 然后在不同的磁力光整加工工艺参数下，利用 XK7136C 数控铣床改造的磁力光整加工系统，采用雾化法制备的新型 Al2O3 / 铁基球形磁性磨料对钛合金试样进行磁力光整加工，分析加工后钛合金试样的粗糙度、表面形貌以及残余应力，并确定最佳工艺参数。结果表明：当磁力光整加工工艺参数分别为主轴转速 1 000.00 r / min，加工间隙 1.50 mm，进给速度 15.00 mm / min 时，磁力光整加工效果最好，钛合金试样表面粗糙度由初始的 0.6 μm 降低到 0.065 μm，试样表面均匀，划痕和表面缺陷被有效去除，达到接近镜面效果。试样表面的残余应力由最初的拉应力+297.4 MPa 转变为压应力?237.8 MPa。利用磨削加工和磁力光整加工技术对 SLM 制备的 TC4 钛合金试样进行光整加工，可有效改善工件表面完整性，提高工件表面质量。 |
| 关键词: 选区激光熔化(SLM) TC4 钛合金 磁力光整加工 响应曲面法 表面粗糙度 |
| DOI：10.11933/j.issn.1007?9289.20220127001 |
| 分类号:TG176 |
| 基金项目: |
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| Surface Quality of SLM TC4 Titanium Alloy Surface by MAF |
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CHEN Haoxin, ZHANG Guixiang, LIU Ning, JIANG Linzhi, ZHU Peixin, DU Jiajing
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School of Mechanical Engineering, Shandong University of Technology, Zibo 255000 , China
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| Abstract: |
| To study the influence of the magnetic finishing process on the surface integrity of TC4 titanium alloy prepared by selective laser melting (SLM), response surface analysis (RSA) tests of three factors and levels were conducted on TC4 titanium alloy samples prepared by SLM using the response surface method. The effects of various test factors on the surface integrity were analyzed, and the optimal processing parameters of TC4 titanium alloy prepared by magnetic finishing SLM were determined. TC4 powder of 15-53 μm diameter was used as SLM forming material, and the samples were prepared using a 67° rotating scanning strategy of 30 μm thickness on SLM?125HL equipment. After sample preparation, prior to the magnetic finishing process, the TC4 titanium alloy sample prepared by SLM was rough ground using a CNC forming grinder. The grinding process reduces the sample surface roughness from 6 μm (after SLM forming) to approximately 0.6 μm. The rough surface with defects such as spheroids and pits evolved into a fine surface with scratches and pores. Subsequently, under different magnetic finishing process parameters, on the magnetic finishing system modified by a XK7136C CNC milling machine, the new Al2O3 / iron-based spherical magnetic abrasive prepared using an atomization method was adsorbed on the slotted magnetic pole, and the magnetic finishing process test was conducted on the rough ground sample. The RSA method involving three factors and levels was utilized in the test. A total of 17 groups of tests were conducted, 5 groups of which were focused on the center test. The test processing parameters were optimized according to the Box-Behnken analysis principle from the RSA method, and the sample surface roughness was measured and analyzed using observational instruments such as a hand-held roughness meter, metallographic microscope, and a white light interferometer. The surface morphology change throughout processing was subsequently observed. The change of residual stress on the sample surface before and after machining was detected using a stress tester. By analyzing surface roughness changes, surface morphology and residual stress of the samples before and after processing, the optimal process parameters for TC4 titanium alloy prepared by magnetic finishing SLM were obtained. Verification results demonstrate that the obtained optimal test parameters are true and effective. Under optimal process parameters, that is, when the precise magnetic finishing process parameters are: spindle speed 1 000.00 r / min, machining gap 1.50 mm, and feed rate 15.00 mm / min, the magnetic finishing effect is the best. The surface roughness of the TC4 titanium alloy sample prepared by SLM, increases from the initial Ra of 0.6 μm to 0.065 μm. The sample surface is uniform, and scratches and surface defects are effectively removed, to achieve a mirror like effect. Among the three magnetic finishing process parameters, the machining gap, feed and spindle speed have the greatest impact on the sample surface integrity. The residual stress on the TC4 Titanium Alloy Specimen surface prepared by SLM changed from an initial tensile stress of +297.4 MPa to a compressive stress of ?237.8 MPa. Test results demonstrate that using the RSA method, the sample is polished by grinding and magnetic finishing technology, and the influence of various factors on the surface roughness of the specimen after magnetic polishing is obtained. Finally, the optimal magnetic polishing process parameters are obtained, the workpiece surface roughness is effectively reduced, and the residual stress on the workpiece surface changed from the initial tensile stress to the compressive stress, therefore, this process effectively improves the surface integrity and quality of the workpiece. |
| Key words: selective Laser melting(SLM) TC4 titanium alloy magnetic abrasive finishing response surface method surface roughness |
