Taguchi Optimization of Electrolytic Plasma Hardening Process Parameters on Ti-6Al-4V Alloy: Microstructure and Mechanical Properties

Herein, the effects of electrolytic plasma treatment (EPT) on the hardness dis-tribution, wear resistance, and surface morphologies of titanium alloy (Ti-6Al-4V) at three different thermal cycles (4-5-6 times) are investigated. The microstructure is controlled by heat temperature and modification times of thermal cycles depending on EPT processing parameters. A novel technique to modify Ti-6Al-4V alloy by the process of EPT successfully occurs. The results show that the phase transformation is shown as follows: fine a and beta for the low thermal cycle-> irregular martensite a' for the high thermal cycle-> complete zigzag martensite a' for the max thermal cycle. The hardness is increased from 350 110HV0.05 to 530 1 10HV0.05 after the modification. Wear tests are conducted according to the Taguchi L9 (3 boolean AND 3) orthogonal array. Three parameters (load, sliding speed, and sample type) with three levels examine wear rate and coefficient of friction. Optimum levels are obtained by Taguchi analysis from the experimental results. In addition, an analysis of variance is performed to find the effectiveness of the parameters. The wear surfaces are analyzed by scanning electron microscope. After the analysis, the best result is obtained in five thermal cycles.

Automated summary

In this study, the effects of electrolytic plasma treatment (EPT) on the hardness distribution, wear resistance, and surface morphologies of Ti-6Al-4V alloy at different thermal cycles were investigated. The results showed that the microstructure of the alloy could be controlled by adjusting the heat temperature and modification times of the thermal cycles during EPT processing. The hardness of the alloy was increased after the modification and the wear rate and coefficient of friction were examined through wear tests.