TRIBOLOGI TKM4094 PRINSIP DASAR TRIBOLOGI
Dosen Pengampu Khairul Anam, ST., MSc. Laboratorium Sentral Mesin, Gedung Mesin I, Lantai I Jl. MT Haryono No. 167, Malang 65145 No. HP : +6281336327969
Email :
[email protected] anamesin.lecture.ub.ac.id
Tujuan Memberikan pemahaman tentang gesekan, aus dan pelumasan serta pengaruhnya dalam komponen mesin.
Pokok Bahasan Prinsip dasar tribologi
Gesekan Aus Pelumasan
Tribologi pada kontak dengan kinematika rendah Tribologi pada kontak dengan kinematika tinggi Efisiensi pelumasan
Referensi Introduction to Tribology_Bharat Bhushan
Tribology in Machine Design_TA Stolarski
Penilaian Kehadiran 10%
Quiz 25% Tugas 25% UAS 40%
HP WAJIB DI SILENT ATAU DI NON-AKTIFKAN!
Tribologi • Object • Who
• Object • Who What How many/
• Result • Analysis
How much
Why
How • When • Where
Prinsip dasar tribologi Tribologi dikenalkan pertama kali oleh Jost (1966)
Tribologi berasal dari bahasa yunani “TRIBOS” yang berarti “BERGESEKAN” Tribologi adalah cabang ilmu desain mesin (friction, wear dan lubrication)
Prinsip dasar tribologi
Prinsip dasar tribologi Elemen mesin yang harus mempertimbangkan tribologi ◦ Bantalan luncur
Prinsip dasar tribologi ◦ Bantalan gelinding
Piston
Prinsip dasar tribologi ◦ Cam
Friction Drive
Prinsip dasar tribologi ◦ Roda Gigi
Prinsip dasar tribologi ◦ ◦ ◦ ◦ ◦ ◦ ◦
Rem Kopling Mur-Baut Seal Semir Menulis Berjalan
Prinsip dasar tribologi Koefisien Gesek dan Keausan ◦ Struktur (properti material) ◦ Kondisi saat mesin bekerja (beban, temperature, waktu, dan lain-lain) ◦ Interaksi antar komponen
Prinsip dasar tribologi Gaya Gesek (tanpa pelumasan) ◦ Gaya gesek selalu berlawanan arah dengan perpindahan ◦ F = fW Dimana: F = Gaya Gesek f = Koefisien Gesek W = Gaya Normal ◦ Gaya gesek tidak tergantung pada luas kontak
The Nature of Surface
Chemical Reaction The nature of Surface
Surface Texture Macro Micro
Kekasaran Permukaan American National Standards Institute (ANSI) International Standardization Organization (ISO)
The Future of Tribology
PRACTICAL OBJECTIVES OF TRIBOLOGY
FRICTION
TRIBOLOGY TRIANGLE
FRICTION What is friction?
It’s a FORCE. Occurs whenever two objects are IN CONTACT with each other. It’s the resistance to movement. It SLOWS objects down.
24
FRICTION Let’s use THE SAME FORCE to move the box on:
higher friction wooden floor
lower friction ice
In which case friction is higher? WHY? Which one will slide further? 25
LUBRICATION Why do we need it? lower the friction prevent wear
↓ wear
↓ friction
remove heat and contamination
WEAR
What is wear?
It’s the removal of material from a solid surface by the action of another surface. 27
WEAR MECHANISMS Adhesive ◦ Low contact pressures ◦ Augmented asperities
Abrasive ◦ High contact pressures ◦ Wear tracks
TYPES OF MOTION There are two types of motion between two moving parts.
● Sliding motion e.g :- Piston in IC engine ●Rolling motion e.g :- Bearings, wheels of automobiles
TRIBOLOGY IN PISTON RINGS AND CYLINDER LINER Cylinder liner is fixed one and piston will slide up and down inside on it. Friction exists between these parts , it results in
wear. It can be reduced by applying lubricant.
RECENT DEVELOPMENTS IN TRIBOLOGY Soybean oil as future lubricant for IC engines. Chemical Vapor Deposition (CVD) Physical Vapor Deposition (PVD)
SOYBEAN OIL AS FUTURE LUBRICANT FOR IC ENGINES Soybean oil is a vegetable oil extracted from soybean seeds. It is easily available at low price. PROPERTIES OF SOYBEAN OIL :> It has a high viscosity index up to 223. > Has comparatively high flash point 610°F. > Has good fire point about 650°F. > It has high pour point, it can be reduced by winterizing the soybean oil.
ADVANTAGES OF SOYBEAN OIL Soybean oil is biodegradable, in general it is less toxic.
It is a renewable oil, so it reduces dependency of foreign petroleum products.
Ease of processing.
CHEMICAL VAPOUR DEPOSITION CVD is used to grow a thin layer of advanced materials on the surface of a substrate. Application:Integrated circuits, electronic devices and sensors.
Catalysts Micromachines, fine powder and ceramic powder protective coatings.
CHEMICAL VAPOUR DEPOSITION
Thin film is formed from gas phase components.
CHEMICAL VAPOUR DEPOSITION Two types of CVD:LPCVD (Low Pressure CVD ) :- Good uniformity, Used for poly-Si, oxide, nitride. PECVD (Plasma Enhanced CVD ) :- Low temperature process and high deposition rate. Used for oxide, nitride, etc.
CHEMICAL VAPOUR DEPOSITION Pressure sensor
Resistance-heated furnace Quartz tube Trap To exhaust Si Wafers
Pump
Gas control system
Source gases
LPCVD Systems
PHYSICAL VAPOUR DEPOSITION PVD is a fundamentally a vaporization coating technique, involving transfer of material on an atomic level. It is an alternative process to electroplating. The process is similar to chemical vapor deposition (CVD) except for the raw materials. i.e. the material that is to be deposited starts in solid form, whereas in CVD the precursors are introduced to the reaction chamber in gaseous state.
APPLICATIONS OF PVD PVD coatings are used to improve Hardness, Wear Resistance, Oxidation Resistance.
Thus, such coatings used in variety of applications such as :Aerospace Automotive Surgical/medical Dies and moulds for all manner of material processing Cutting tools Fire arms
ECONOMIC ASPECTS OF TRIBOLOGY The LUBRICANT REPORT estimated an amount exceeding 500 million pounds can be saved in the civilian sector of UK by research in tribology. The estimated 11 % total savings in annual US energy consumption is equivalent to some 16 billion US dollars by an expenditure in research and development o f an estimated twenty-four million dollars. Analysis of the failure of boiler tubes indicate that about one-third of all occurrences were due to erosion. In UK, the application of tribological principles can effect national energy savings. These are estimated at 468 to 700 million pounds per annum.
IMPACT OF TRIBOLOGY Since the publication of the Lubrication Report there has been an increasing awareness throughout industry of the subject of tribology. In the UK the National Centre for Tribology and Industrial Units of Tribology have been set up to provide advice t o industry on the utilisation of existing knowledge. Tribology is now recognized universally and President Carter of U.S.A. declared it to be a generic technology underlying many industrial sections and the prospectus for an Industrial Tribology Institute at Rensselaer Technology Center has been presented.
