Claim Missing Document
Check
Articles

Found 2 Documents
Search

Pengaruh Waktu Tahan Dan Penambahan Kadar Garam Dapur (NaCl) Dalam Media Pendingin Air Pada Proses Hardening Terhadap Sifat Mekanik Dan Struktur Mikro Baja Karbon Rendah Richard A M Napitupulu; Suriady Sihombing; Charles Manurung; Jonner Togatorop
SPROCKET JOURNAL OF MECHANICAL ENGINEERING Vol 1 No 1 (2019): Edisi Agustus 2019
Publisher : Program Studi Teknik Mesin, Universitas HKBP Nommensen, Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3694.172 KB) | DOI: 10.36655/sproket.v1i1.36

Abstract

This study aims to determine the effect of salt (NaCl) in water cooling media with different levels of 10%, 16% and 25% against the hardness level of low carbon steel tested with Vickers after hardening in the hardening process and to determine the proportion of media which coolant produces the highest hardness from the use of water cooling media which is added to different levels of NaCl. The independent variable in this study is the amount of salt (NaCl) dissolved in water cooling media with different percentages, namely 10%, 16% and 25%. While the dependent variable is the value of the hardness of the material tested with Vickers. Hardness in the hardening process with water cooling media which added different salt (NaCl), 10%, 16% and 25% is 185.02 VHN, 229 VHN and 284 VHN. From the results of the study it was found that there was an effect of the salt content (NaCl) in the water cooling media on the level of hardness in the hardening process of low carbon steel. Higher level of salt will increase value of hardness. The highest hardness was achieved in cooling media with a concentration of 25% NaCl that is equal to 284 VHN followed by cooling media with a concentration of 16% NaCl of 229 VHN and the lowest was a cooling medium with a concentration of 10% NaCl of 185.02 VHN.
Analisa Kekuatan Bahan Komposit Yang Diperkuat Serat Bambu Menggunakan Resin Polyester Dengan Memvariasikan Susunan Serat Secara Acak Dan Lurus Memanjang Rokki Manurung; Sutan Simanjuntak; Jesayas Sembiring; Richard A M Napitupulu; Suriady Sihombing
SPROCKET JOURNAL OF MECHANICAL ENGINEERING Vol 2 No 1 (2020): Edisi Agustus 2020
Publisher : Program Studi Teknik Mesin, Universitas HKBP Nommensen, Medan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (316.236 KB) | DOI: 10.36655/sproket.v2i1.296

Abstract

Composites are materials which are mixed with one or more different and heterogeneous reinforcement. Matrix materials can generally be polymers, ceramics and metals. The matrix in the composite serves to distribute the load into all reinforcing material. Matrix properties are usually ductile. The reinforcing material in the composite has the role of holding the load received by the composite material. The nature of the reinforcing material is usually rigid and tough. Strengthening materials commonly used so far are carbon fiber, glass fiber, ceramics. The use of natural fibers as a type of fiber that has advantages began to be applied as a reinforcing material in polymer composites. This study seeks to see the effect of the use of bamboo natural fibers in polyester resin matrix on the strength of polymer composites with random and straight lengthwise fiber variations. From the tensile test results it can be seen that bamboo fibers can increase the strength of polymer composites made from polyester resin and the position of the longitudinal fibers gives a significantly more strength increase than random fibers.