Study on Formation of High-performance Metal Mold Surface by EDM with Hybrid Metal Powder Mixed Fluid

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H02050
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Okayama University
• Principal Investigator: Okada Akira 岡山大学, 環境生命自然科学学域, 教授 (60263612)
• Co-Investigator(Kenkyū-buntansha): 岡本 康寛 岡山大学, 環境生命自然科学学域, 准教授 (40304331) ; 北田 良二 崇城大学, 工学部, 教授 (60540276) ; 篠永 東吾 岡山大学, 環境生命自然科学学域, 助教 (60748507)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 放電加工 / 金型

Outline of Final Research Achievements

This study found firstly that a hard surface layer containing chromium carbide can be formed on the EDM finished surface by using a chromium powder mixed working fluid. Then, the effect of hybrid powder-mixed EDM with using chromium powder and silicon one, was investigated, and sufficiently small surface roughness with a practical level for metal mold could be obtained.
On the other hand, by applying EDM conditions with large electrode wear, the formation of surface layer containing electrode components was also succeeded. By using a chromium electrode and a cemented WC one in sequence, we succeeded the formation of a two-layer structure surface layer containing chromium carbide and tungsten carbide.
Furthermore, in order to quantitatively evaluate the releasability of molded resin from the finished surface of metal mold, we built a new device to measure the resin releasing force, and accurate evaluation of the mold releasability from metal surface became possible.

Free Research Field

特殊加工

Academic Significance and Societal Importance of the Research Achievements

放電加工を用い，加工液に混入した金属粉末や電極材質の成分を仕上げ面に含有できる現象を確認し，そのメカニズムを解明したところに学術的な意義がある．また，加工液の熱分解炭素と化合した硬質炭化物を含有する表面層を形成できること，異なる電極を順に用いることで2層構造表面層を創成できることは産業的な意義も大きい．放電加工のみで金型形状創成から表面仕上げ・改質が達成できる可能性があり，金型加工プロセス全体の高能率低コスト化が期待できる．