Cathodic discharge plasma in electrochemical jet machining: Phenomena, mechanism and characteristics

Zhan, Shunda1,2; Lyu, Zhaozhi1; Dong, Bangyan1,2; Liu, Weidong3; Zhao, Yonghua1,4

2023-04-01

10.1016/j.ijmachtools.2023.104015

INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE   影响因子和分区

0890-6955

1879-2170

An ultrahigh voltage is frequently required in electrochemical jet machining (EJM) to produce extreme current densities (>900 A/cm2 for this study) to achieve maximum dissolution rates. However, such a high electric field easily induces a cathodic discharge at the nozzle, and the generation mechanism and characteristics remain unexplored. For the first time, this study shows a direct visualisation of the hydrogen evolution and cathodic discharge in EJM using high-speed photography. An in-depth analysis of the discharge behaviour was carried out based on electrical monitoring, temperature measurement, and characterisation of the resulting changes in the electrode surface. It was revealed that the current density threshold determines the discharge ignition. Discharge occurs preferentially at the inner edge of the nozzle end face, which can cause nozzle wear and reduce local-isation of anode workpiece dissolution. The discharge intensity can be controlled by varying the applied voltage and pulse frequency. The electrolyte flow velocity and gap distance influence the discharge behaviour. With appropriate process control, cathodic plasma can enhance the EJM performance while minimising its negative impact. Furthermore, cathodic discharge can be significantly suppressed by designing the geometry of the nozzle tip to avoid local electric field concentration.

Electrochemical jet machining Extreme current density Hydrogen gas evolution Cathodic discharge plasma Machining characteristics

SCI ; EI

英语

第一 ; 通讯

National Key R & D Program of China[2021YFF0501700] ; National Natural Science Foundation of China (NSFC)[51905255] ; Shenzhen Science and Technology Program[GJHZ20200731095204014] ; Shenzhen Science and Technology Innovation Commission[JCYJ20190809143217193]

Engineering

Engineering, Manufacturing ; Engineering, Mechanical

WOS:000959456000001

ELSEVIER SCI LTD

20231213753693

Dissolution ; Electric discharges ; Electrodes ; Flow velocity ; High speed photography ; Hydrogen ; Nozzle design ; Temperature measurement ; Threshold current density

Structural Design:408 ; Fluid Flow:631 ; Fluid Flow, General:631.1 ; Electricity: Basic Concepts and Phenomena:701.1 ; Electric Batteries and Fuel Cells:702 ; Photography:742.1 ; Chemical Operations:802.3 ; Chemical Agents and Basic Industrial Chemicals:803 ; Chemical Products Generally:804 ; Mechanical Variables Measurements:943.2 ; Temperature Measurements:944.6

ENGINEERING

Web of Science

1.Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China
2.Harbin Inst Technol, Sch Mechatron Engn, Harbin 150001, Peoples R China
3.Civil Aviat Univ China, Coll Aeronaut Engn, Tianjin 300300, Peoples R China
4.Southern Univ Sci & Technol, 1088 Xueyuan Rd, Shenzhen 518055, Guangdong, Peoples R China

Zhan, Shunda,Lyu, Zhaozhi,Dong, Bangyan,et al. Cathodic discharge plasma in electrochemical jet machining: Phenomena, mechanism and characteristics[J]. INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE,2023,187.

Zhan, Shunda,Lyu, Zhaozhi,Dong, Bangyan,Liu, Weidong,&Zhao, Yonghua.(2023).Cathodic discharge plasma in electrochemical jet machining: Phenomena, mechanism and characteristics.INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE,187.

Zhan, Shunda,et al."Cathodic discharge plasma in electrochemical jet machining: Phenomena, mechanism and characteristics".INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE 187(2023).