Analysis of Fatigue and Microhardness in Metallic Powder Mixed EDM

• 作者: Ahmad Majdi Abdul-Rani Alexis Mouangué Nanimina Bonaventure Danoumbé Djimako Bongo Nandiguim Lamaï Togdjim Jonas
• 来源期刊: 应用科学(英文)
• 学科: 工学
• 关键词: PMEDM FATIGUE Micro-Hardness Discharge Current Gap Voltage ON-Time
• 年，卷（期）: 2020,（10）
• 页码范围: 613-624
• 页数: 12页
• 分类号: TG1

摘要

The objective of this work research is to investigate the potential of using metallic powder mixed with electrical discharge machining (EDM) dielectric when machining hard electrically conductive materials. Nowadays, the development of industries requires hard materials for various applications. Machining the hard materials using the traditional processes lead to tool break and poor machined product. Even<span style="font-family:Verdana;"> when</span><span style="font-family:Verdana;"> the conventional EDM can machine hard material as long as it </span><span style="font-family:Verdana;">is</span><span style="font-family:Verdana;"> electrically conductive materials, the machined parts still present drawbacks. Metallic powder mixed with EDM dielectric (PMEDM) was hypothesized to improve the machined part. The presence of metallic powder ensures uniform distribution of spark and the electrical density of the spark decreases which reduces craters, cracks and voids on machined surface. The transfer and deposit of alloying elements during powder mixed electrical discharge machining improve the machined surface properties particularly micro-hardness and fatigue. Discharge current (IP), gap voltage (GapV), ON-time (ON) and aluminum powder are selected as machined variable parameters and the output responses are fatigue performance, micro-hardness and surface topography. The workpiece material selected </span><span style="font-family:Verdana;">is </span><span style="font-family:Verdana;">molybdenum high speed steel. Micro-hardness was determined using micro-hardness tester device. The fatigue performance was determined using empirical equation. Analysis of material transfer was done using energy dispersive spectroscopy (EDS) attached to FESEM. EDS analysis involves the generation of an X-ray spectrum from the entire scan area of the SEM. The use of PMEDM improve</span><span style="font-family:Verdana;">d</span><span style="font-family:Verdana;"> the fatigue, the micro-harness and the machined surface morphology as the abo