JENIS MATERIAL PAHAT POTONG DAN RUN OUT TERHADAP KEKASARAN PERMUKAAN BENDA KERJA SILINDER PADA PROSES BUBUT

(1)Hendra, (2) Sutarmadi, (3) Anizar Indriani, (4) Hernadewita
(1)(2) Program Studi Teknik Mesin Universitas Bengkulu
(3) Program Studi Teknik Elektro Universitas Bengkulu
(4) Sekolah Tinggi Manajemen Industri Departemen Perindustian Jakarta
Jl. W.R. Supratman Kandang Limun Bengkulu
Telepon : (0736) 344087, 22105 - 227
Email : h7f1973@yahoo.com

Abstract

Machining process is part of the production process where cutting process of work piece is
done by using machine tools. Machine tools are used in the machining process includes lathe
machines, milling machines, shaping machines, drilling machines and other machine tools.
For a cylindrical work piece the cutting process can be done by using a lathe. Lathe process
can make cylindrical objects, holes, taper and other forms. In the cutting process of work
piece with a lathe machine are required high accuracy and precision especially for work
piece such as shafts , pistons and objects that serve as a connecting other components.
Work piece with high accuracy and precision can be obtained by use the reliable of machine
tools, cutting condition, the selection of machining elements and material of cutting tools;
operators have a skill for operation of machine tools. Cutting conditions such as mounting
work pieces that are not center (run out) or overhang of work piece with strong pressure
between head stock and tail stock can be resulting deflection. Run out and deflection
happened can be cause the cutting force is not uniform. Therefore cause damage to the
work piece and machine. Damage on the work piece can be seen from the quality of the
cutting (surface roughness) and for machine on the case of chatter or vibration arising from
the cutting force. In this paper we will focus to determine the effect of cutting tools material
and run out of material on the surface roughness where as machining element used is the
depth of cut and feeding. Work piece used is made of medium carbon steel.

Keyword: Surface Roughness, Feeding, Dept of Cut, Lathe Machine and Cutting Tools.

http://www.scribd.com/doc/214015099/JENIS-MATERIAL-PAHAT-POTONG-DAN-RUN-OUT-TERHADAP-KEKASARAN-PERMUKAAN-BENDA-KERJA-SILINDER-PADA-PROSES-BUBUT

MAKSIMUM TEGANGAN THERMAL PADA PROSES PENCELUPAN CERAMIC STALK DI LOW PRESSURE DIE CASTING MACHINE

Hendra
Program Studi Teknik Mesin Fakultas Teknik Universitas Bengkulu
Email : mpe2_boy@yahoo.com


Abstract
Low pressure die casting is process to make the axi-simmetric product such as cylinder head, piston, brake drum and etc. The process is injected the molten metal with high speeds and pressure into a metallic die. The low pressure die casting process has some advantages as a low-cost and high-efficiency precision forming technique. The low pressure die casting having the permanent die and filling systems are placed over the furnace containing the molten alloy. The filling of the cavity is obtained by forcing using the pressurized gas to order a rise the molten metal into a tube, which connects the die to the furnace. The tube called stalk made from ceramics because ceramics has high temperature resistance and high corrosion resistance. However, care should be taken for the thermal stress when the tube is dipped into the molten metal. To reduce the risk of fracture it is important because fracture may happen due to the thermal stresses. In this paper, thermo-fluid analysis is performed to calculate surface heat transfer coefficient. Then, the finite element method is applied to consider the thermal stresses when the stalk is dipped into the crucible with varying the dipping speeds. It is found that the stalk with slowly dipping is better than fast dipping to reduce the thermal stress.

Keywords: Thermal Stress, Stalk, Low Pressure Die Casting Machine, Finite element method

full paper : http://www.scribd.com/doc/214013082/Jurnal-Mechanical-Maret-2012-1-2

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