Ahmad Humaizi Hilmi
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Ahmad Humaizi Hilmi
Official Name
Ahmad Humaizi, Hilmi
Alternative Name
Hilmi, Ahmad Humaizi
Hilmi, A.
Humaizi, Ahmad
Hilmi, A. H
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Scopus Author ID
57193311438
Researcher ID
W-1988-2019

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  • Publication
    Explosive Pressing Experiment and Its Challenges to Conduct it on University Level
    ( 2020-03-20)
    Ahmad Humaizi Hilmi
    ;
    Yusuf M.A.
    Typical press force for hydraulic press machine for most universities are around 10 to 30 ton. For higher load, student uses Ultimate Testing Machine (UTM). Typical press force for UTM for higher learning institution is 300 ton. To obtain more press force, the specimen must be small. This is according to force equation where the smaller the surface area, the higher the force generated on it. However, the problem with small specimen is that it is difficult for researchers to do further investigations for hardness test, tensile test and microstructural analysis. Besides, there is a limit to maximum force a UTM machine can give. This paper presents steps for doing experiments using explosive pressing at university level. The explosive pressing apparatus was an improved designed by the same author. This experiment uses an amount of explosive that is place at top of the apparatus. The experiment is done underground for safety purposes. Explosive handling was done with help from authorized explosive expert. Major benefits of explosive pressing are larger samples can be pressed and the press force is very high. This paper will discuss the steps to do experiment and the challenges while doing explosive pressing using this apparatus. This paper will also show that higher pressing force can lead to finer microstructure of material being pressed.
  • Publication
    A method to press powder at 6000 ton using small amount of explosive
    ( 2017-12-04)
    Ahmad Humaizi Hilmi
    ;
    Nor Azmaliana Azmi
    ;
    Ariffin Ismail
    Large die hydraulic press forces are one of the key instruments in making jumbo planes. The machine can produce aircraft components such as wing spars, landing gear supports and armor plates. Superpower nations such as USA, Russia, Germany, Japan, Korea and China have large die hydraulic press which can press 50,000 tons. In Malaysia, heavy-duty press is available from companies such as Proton that builds chassis for cars. However, that heavy-duty press is not able to produce better bulkhead for engines, fuselage, and wings of an aircraft. This paper presents the design of an apparatus that uses 50 grams of commercial grade explosives to produce 6000 tons of compaction. This is a first step towards producing larger scale apparatus that can produce 50,000-ton press. The design was done using AUTODYN blast simulation software. According to the results, the maximum load the apparatus can withstand was 6000 tons which was contributed by 50 grams of commercial explosive(Emulex). Explosive size larger than 50 grams will lead to catastrophic failure. Fabrication of the apparatus was completed. However, testing of the apparatus is not presented in this article.