scholarly journals Fabrication of Functionally Graded Diamond/Al Composites by Liquid–Solid Separation Technology

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3205
Author(s):  
Hongyu Zhou ◽  
Yaqiang Li ◽  
Huimin Wang ◽  
Minrui Ran ◽  
Zhi Tong ◽  
...  
Keyword(s):  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Functionally Graded ◽  
Cover Plate ◽  
Microelectronic Device ◽  
Separation Technology ◽  
Hermetic Packaging ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Thermal Stability Of

The electronic packaging shell, the necessary material for hermetic packaging of large microelectronic device chips, is made by mechanical processing of a uniform block. However, the property variety requirements at different positions of the shell due to the performance have not been solved. An independently developed liquid–solid separation technology is applied to fabricate the diamond/Al composites with a graded distribution of diamond particles. The diamond content decreases along a gradient from the bottom of the shell, which houses the chips, to the top of the shell wall, which is welded with the cover plate. The bottom of the shell has a thermal conductivity (TC) of 169 W/mK, coefficient of thermal expansion (CTE) of 11.0 × 10−6/K, bending strength of 88 MPa, and diamond content of 48 vol.%. The top of the shell has a TC of 108 W/mK, CTE of 19.3 × 10−6/K, bending strength of 175 MPa, and diamond content of 15 vol.%, which solves the special requirements of different parts of the shell and helps to improve the thermal stability of packaging components. Moreover, the interfacial characteristics are also investigated. This work provides a promising approach for the preparation of packaging shells by near-net shape forming.

Characterization of Al3Fe Particle within Al-Al3Fe Functionally Graded Material Fabricated by Semi-Solid Forming

2005 ◽  
Vol 475-479 ◽  
pp. 1503-1506 ◽  
Author(s):  
Koichi Matsuda ◽  
Yoshimi Watanabe ◽  
Kazuhisa Yamagiwa ◽  
Yasuyoshi Fukui
Keyword(s):  
Volume Fraction ◽  
Functionally Graded ◽  
Shore Hardness ◽  
Graded Materials ◽  
Before And After ◽  
Graded Material ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Semi Solid

Near net shape forming of Al-Al3Fe functionally graded materials (FGMs) have been studied. FGM billets fabricated by a centrifugal method were extruded under the condition of a mixture of molten Al eutectic and solid Al3Fe particles. Both distribution and profile of Al3Fe particles were characterized by and the variation of volume fraction of Al3Fe particles was observed. Shore hardness of the Al matrix was also measured to evaluate the strength of the FGM before and after the semi-solid forming associated with the character of distributed Al3Fe particles. It was confirmed that Shore hardness increased with increasing the volume fraction of Al3Fe particles and after the semi-solid forming than before. This was due to the fact that Al3Fe particles after the semi-solid forming became fine by shear stress introduced by liquid Al flow.

Near-Net Shape Forming of Functionally Graded Cemented Carbide, Sinter-Bonded on Steel

1999 ◽  
Vol 308-311 ◽  
pp. 487-492 ◽  
Author(s):  
A. Ikegaya ◽  
K. Tsuda ◽  
K. Uchino ◽  
T. Miyagawa ◽  
Y. Suehiro
Keyword(s):  
Functionally Graded ◽  
Cemented Carbide ◽  
Near Net Shape ◽  
Net Shape Forming

On thermal stability of plates with functionally graded coefficient of thermal expansion

2016 ◽  
Vol 60 (2) ◽  
pp. 313-335 ◽  
Author(s):  
Abdelmoumen Anis Bousahla ◽  
Samir Benyoucef ◽  
Abdelouahed Tounsi ◽  
S.R. Mahmoud
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Functionally Graded ◽  
Thermal Stability Of

In Situ Preparation and Mechanical Properties of (ZrB2+ZrC)/Zr3[Al(Si)]4C6 Composites

2014 ◽  
Vol 602-603 ◽  
pp. 438-442
Author(s):  
Lei Yu ◽  
Jian Yang ◽  
Tai Qiu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Bending Strength ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Linear Increase ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Uniform Microstructure

Fully dense (ZrB2+ZrC)/Zr3[Al (Si)]4C6 composites with ZrB2 content varying from 0 to 15 vol.% and fixed ZrC content of 10 vol.% were successfully prepared by in situ hot-pressing in Ar atmosphere using ZrH2, Al, Si, C and B4C as raw materials. With the increase of ZrB2 content, both the bending strength and fracture toughness of the composites increase and then decrease. The synergistic action of ZrB2 and ZrC as reinforcements shows significant strengthening and toughing effect to the Zr3[Al (Si)]4C6 matrix. The composite with 10 vol.% ZrB2 shows the optimal mechanical properties: 516 MPa for bending strength and 6.52 MPa·m1/2 for fracture toughness. With the increase of ZrB2 content, the Vickers hardness of the composites shows a near-linear increase from 15.3 GPa to 16.7 GPa. The strengthening and toughening effect can be ascribed to the unique mechanical properties of ZrB2 and ZrC reinforcements, the differences in coefficient of thermal expansion and modulus between them and Zr3[Al (Si)]4C6 matrix, fine grain strengthening and uniform microstructure derived by the in situ synthesis reaction.

Mechanical Design for Accuracy of Linkage Servo Press for Near-Net Shape Forming

2018 ◽  
Author(s):  
Jing Tao ◽  
Huanan Qian ◽  
Suiran Yu
Keyword(s):  
Mechanical Design ◽  
Structure Design ◽  
Tolerance Allocation ◽  
Component Level ◽  
Eccentric Load ◽  
Servo Press ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Heavy Loads

The accuracy of machine is important to achieving highly accurate shapes. This paper is focused on mechanical design of highly accurate mechanical linkage servo press applicable to (near-)net shape forming. The effects of geometric errors, deformations under heavy loads and ram tilting are analyzed. A top-down design for accuracy approach is proposed: First, accuracy model for identification of inaccuracy-causing factors and their interlinking relations is developed. Then, based on this model, top accuracy index are decomposed and translated into structure design specifications at component level. Both analytic and simulation methods are employed for design for accuracy in aspects of dimensional and geometric tolerance allocation, stiffness synthesis and anti-eccentric load capability. A case study of mechanical design for accuracy of a six-linkage mechanical servo press is also presented to demonstrate and test the proposed design approaches.

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