Base material for printed circuits. Specifications

Whisker and fiber reinforcement has been established as an effective toughening concept for monolithic structural ceramics to overcome limited fracture toughness and brittleness. SiC whiskers in particular combine both high strength and elastic moduli with good thermal stability and are compatible with most oxide and nonoxide matrices. As the major toughening mechanisms - crack branching, deflection and bridging - in SiC whiskenreinforced Al2O3 and Si3N41 are critically dependent on interface properties, a detailed TEM investigation was conducted on whisker/matrix interfaces in these all-ceramic- composites.In this study we present HREM images obtained at 400 kV from β-SiC/α-Al2O3 and β-SiC/β-Si3N4 interfaces, as well as preliminary analytical data. The Al2O3- base composite was hotpressed at 1830 °C/60 MPa in vacuum and the Si3N4-base material at 1725 °C/30 MPa in argon atmosphere, respectively, adding a total of 6 vt.% (Y2O3 + Al2O3) to the latter to promote densification.

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Microstructure of resistance spot welding of maraging steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100177635 ◽

1990 ◽

Vol 48 (4) ◽

pp. 900-901

Author(s):

I. Neuman ◽

S.F. Dirnfeld ◽

I. Minkoff

Keyword(s):

Maraging Steel ◽

Spot Welding ◽

Lath Martensite ◽

Base Material ◽

Aging Treatment ◽

High Strength ◽

Maraging Steels ◽

Heat Treated ◽

Current Cycle ◽

Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

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Optimization of Process Parameters in Stir Casting of Hybrid Metal Matrix (LM25/SiC/B4C) Composite Using Taguchi Method

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v13i9.5777 ◽

2017 ◽

Vol 13 (9) ◽

pp. 6475-6479

Author(s):

M. Arulraj ◽

P.K. Palani ◽

L. Venkatesh

Keyword(s):

Taguchi Method ◽

Matrix Material ◽

Base Material ◽

Stir Casting ◽

Aluminium Matrix ◽

Matrix Composites ◽

Design Concepts ◽

Specific Strength ◽

Optimization Of Process Parameters ◽

Reinforcement Material

Aluminium based composites exhibit many attractive material properties such as increased stiffness, wear resistance, specific strength and vibration damping and decreased co-efficient of thermal expansion compared with the conventional aluminium alloys. Aluminium Matrix Composites consist of non-metallic reinforcement which offers advantageous properties over base material. Reinforcements like SiC, B4C and Al2O3 are normally preferred to improve the mechanical properties. Here Aluminum LM25 is selected as matrix material while Silicon carbide and Boron carbide are selected as reinforcement material. The fabrication of aluminium matrix was done by stir casting method. In the present study an attempt has been made to investigate the effect of three major stir casting parameters (stir speed, stir duration and preheated temperature of reinforcement material) on stir casting of Aluminium LM25 - SiC - B4C composite. Experiments were conducted based on Taguchi methodology. Taguchi quality design concepts of L9 orthogonal array has been used to determine S/N ratio and through S/N ratio a set of optimum stir casting parameters were obtained. The experimental results confirmed the validity of Taguchi method for enhancing tensile strength of castings.

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Effective thermal conductivity of open-pore metal foams as a function of the base material

Materials Testing ◽

10.3139/120.110784 ◽

2015 ◽

Vol 57 (10) ◽

pp. 825-836 ◽

Cited By ~ 5

Author(s):

Alexander Martin Matz ◽

Bettina Stefanie Mocker ◽

Norbert Jost ◽

Peter Krug

Keyword(s):

Thermal Conductivity ◽

Effective Thermal Conductivity ◽

Base Material ◽

Metal Foams

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UNITEMP HX

Alloy Digest ◽

10.31399/asm.ad.ni0091 ◽

1964 ◽

Vol 13 (5) ◽

Keyword(s):

Fracture Toughness ◽

Corrosion Resistance ◽

High Temperature ◽

Physical Properties ◽

Base Material ◽

Heat Treating ◽

Operating Conditions ◽

High Temperature Strength ◽

Temperature Performance ◽

Nickel Base

Abstract Unitemp-HX is a nickel-base material recommended for high temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-91. Producer or source: Universal Cyclops Steel Corporation.

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SOMERS LTA COPPER

Alloy Digest ◽

10.31399/asm.ad.cu0407 ◽

1980 ◽

Vol 29 (12) ◽

Keyword(s):

High Temperature ◽

Low Temperature ◽

Physical Properties ◽

Copper Foil ◽

Heat Treating ◽

Dielectric Substrates ◽

Printed Circuits

Abstract SOMERS LTA Copper is a wrought copper foil that can be annealed at 350 F in 15 minutes to the full-soft condition; its use simplifies the manufacture of printed circuits (LTA = Low-Temperature Annealable). LTA Copper is especially useful for foil weights up to and including one ounce per square foot (0.0014-inch thick) for laminating to high-temperature dielectric substrates. This datasheet provides information on composition, physical properties, and elasticity as well as fatigue. It also includes information on forming, heat treating, and machining. Filing Code: Cu-407. Producer or source: Olin Corporation.

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