KOMPOSIT. Tipe-tipe Komposit Berdasarkan Material Penyusunnya. Metal Ceramic Polymer. Powder metallurgy parts combining immiscible metals

Ukuran: px

Mulai penontonan dengan halaman:

Download "KOMPOSIT. Tipe-tipe Komposit Berdasarkan Material Penyusunnya. Metal Ceramic Polymer. Powder metallurgy parts combining immiscible metals"

Verawati Susman
6 tahun lalu
Tontonan:

1 KOMPOSIT Fibers Tipe-tipe Komposit Berdasarkan Material Penyusunnya Matrix phase/reinforc ement Phase Metal Metal Ceramic Polymer Powder metallurgy parts combining immiscible metals Cermets (ceramicmetal composite) Brake pads Ceramic Cermets, TiC, TiCN Cemented carbides used in tools Fiber-reinforced metals SiC reinforced Al2O3 Tool materials Fiberglass Polymer Kevlar fibers in an epoxy matrix Elemental (Carbon, Boron, etc.) Fiber reinforced metals Auto parts aerospace Rubber with carbon (tires) Boron, Carbon reinforced plastics MMC s CMC s PMC s Metal Matrix Composites Ceramic Matrix Comp s. Polymer Matrix Comp s 1

2 Penguatan oleh Fiber Pada umumnya, komposit terdiri dari matriks yang menyatukan material penguat (reinforcing materials). Material penguat yang paling penting adalah berbentuk fiber yang memberikan kekuatan utama komposit. Namun, fungsi material penguat kadang tidak hanya kekuatan akan tetapi juga dalam hal ketahan atau daya hantar panas dan listrik, dan ketahanan korosi. Pertimbangan lainnya adalah kekakuan (stiffness/modulus elasticity) atau berbagai property yang lain. Fiber Reinforced Polymer Matrix Matrix Transfer Load to Reinforcement Temperature Resistance Chemical Resistance Reinforcement Tensile Properties Stiffness Impact Resistance 2

3 Bentuk2 Material Penguat Fibers Penampang lintang bisa lingkaran, persegi, atau hexagonal Diameter --> Panjang --> L/D ratio for chopped fiber much longer for continuous fiber Particulate Partikel kecil yang menghalangi pergerakan dislokasi (pd metal composite) dan memperkuat matriks. For sizes > 1 μm, strength of particle is involves in load sharing with matrix Flakes Flat platelet form Berbagai Pertimbangan Desain Komposit Performansi komposit: Kekuatan, Temperatu, Kekakuan Teknik pembuatan (manufacturing process) Pertimbangan umur (life cycle consideration) Harga (Cost) 3

4 Pertimbangan-Pertimbangan Pemilihan Matrik End Use Temperature Temperatur operasi (penggunaan) Toughness Ketangguhan Cosmetic Issues Tampilan, estetika Flame Retardant Tahan api Processing Method Metode pemrosesan Adhesion Requirements Kebutuhan akan perekat Macam-macam Penguat (reinforcement) Fiber Type Fiberglass Carbon Aramid Textile Structure Unidirectional Woven Braid 4

5 Fibers Glass (1) E-glass: Alumina-calcium-borosilicate glass (electrical applications) S-2 glass: Magnesuim aluminosilicate glass (reinforcements) Glass offers good mechanical, electrical, and thermal properties at a relatively low cost. E-glass S-2 glass Density 2.56 g/cc 2.46 g/cc Tensile Strength 390 ksi 620 ksi Tensile Modulus 10.5 msi 13 msi Elongation 4.8% 5.3% Glass Fibers (2) Jenis fiber yang paling banyak dipergunakan Penggunaan: pipa, tangki, perahu, alat-alat olah raga Kelebihan Low cost Corrosion resistance Low cost relative to other composites: Kekurangan Relatively low strength High elongation Moderate strength and weight Tipa-tipe: E-Glass - electrical, cheaper S-Glass - high strength 5

6 Aramid Fibers (1) Kevlar & Twaron Para aramid fiber characterized by high tensile strength and modulus Excellent Impact Resistance Good Temperature Resistance Density 1.44 g/cc Tensile Strength 400 ksi Tensile Modulus 18 Msi Elongation 2.5% Aramid (Kevlar, Twaron) (2) Penggunaan: high performance replacement for glass fiber Contoh-contoh penggunaan Armor, protective clothing, industrial, sporting goods Keuntungan: higher strength and lighter than glass More ductile than carbon 6

7 Carbon Fiber (1) PAN: Fiber made from Polyacrylonitrile precursor fiber High strength and stiffness Large variety of fiber types available Standard Modulus Intermediate Modulus Density 1.79 g/cc 1.79 g/cc Tensile Strength 600 ksi 800 ksi Tensile Modulus 33 Msi 42 Msi Elongation 1.8 % 1.8 % Carbon Fibers (2) 2nd most widely used fiber Examples aerospace, sporting goods Advantages high stiffness and strength Low density Intermediate cost Properties: Standard modulus: Gpa Intermediate modulus: GPa High modulus: GPa Diameter: 5-8 microns, smaller than human hair Fibers grouped into tows or yarns of 2-12k fibers 7

8 Carbon Fibers (3) Types of carbon fiber vary in strength with processing Trade-off between strength and modulus Intermediate modulus PAN (Polyacrylonitrile) fiber precursor heated and stretched to align structure and remove non-carbon material High modulus made from petroleum pitch precursor at lower cost much lower strength Weight Considerations Aramid fibers are the lightest g/cc Carbon 1.79 g/c Fiberglass is the heaviest 2.4 g/cc 8

9 Strength Considerations Carbon is the strongest ksi Fiberglass ksi Aramids 400 ksi Impact Resistance Kevlar is the toughest Fiberglass Carbon 9

10 Stiffness Considerations Carbon is the stiffest msi Aramids 14 msi Fiberglass msi Cost Considerations Fiberglass is cost effective $ /lb. Aramids $20.00/lb Carbon $30.00-$50.00/lb 10

11 Fabric Structures Woven: other Knit: Braided: Series of Interlaced yarns at 90 to each Series of Interlooped Yarns Series of Intertwined, Spiral Yarns Nonwoven: Oriented fibers either mechanically, chemically, or thermally bonded Woven Fabrics Basic woven fabrics consists of two systems of yarns interlaced at right angles to create a single layer with isotropic or biaxial properties. 11

12 Physical Properties Construction (ends & picks) Weight Thickness Weave Type Components of a Woven Fabric 12

13 Basic Weave Types Plain Weave Basic Weave Types Satin 5HS 13

14 Basic Weave Types 2 x 2 Twill Basic Weave Types Non-Crimp 14

15 Braiding A braid consists of two sets of yarns, which are helically intertwined. The resulting structure is oriented to the longitudinal axis of the braid. This structure is imparted with a high level of conformability, relative low cost and ease of manufacture. Braid Structure 15

add dimensional stability, improve tensile properties, stiffness and

16 Types of Braids Triaxial Yarns A system of longitudinal yarns can be introduced which are held in place by the braiding yarns These yarns will add dimensional stability, improve tensile properties, stiffness and compressive strength. Yarns can also be added to the core of the braid to form a solid braid. 16

17 Kesimpulan Material komposit menjanjikan pilihan desain yang tak terbatas. Pemilihan Matriks, Fiber, dan Preform sangat penting pada prose sdesain. Struktur dapat dihasilkan dengan sifatsifat khusus untuk memenuhi kebutuhan penggunaan. 17

18 Others Fibers (1) Boron High stiffness, very high cost Large diameter microns Good compressive strength Polyethylene - trade name: Spectra fiber Textile industry High strength Extremely light weight Low range of temperature usage Other - Fibers (2) Ceramic Fibers (and matrices) Very high temperature applications (e.g. engine components) Silicon carbide fiber - in whisker form. Ceramic matrix so temperature resistance is not compromised Infrequent use 18

19 Fiber Material Properties Steel: density (Fe) = 7.87 g/cc; TS=0.380 GPa; Modulus=207 GPa Al: density=2.71 g/cc; TS=0.035 GPa; Modulus=69 GPa Fiber Strength 19

dokumen-dokumen yang mirip

BAHAN KOMPOSIT PENDAHULUAN HOME Komposit adalah suatu tipe material yang terjadinya karena pencampuran atau kombinasi beberapa bahan yang menghasilkan sifat-sifat tertentu yang lebih baik yang tidak dimiliki