FEEDSTOCK FLOW CHARACTERIZATION AND PROCESSING OF POROUS NITI BY METAL INJECTION MOULDING (MIM)

2015 ◽  
Vol 76 (11) ◽  
Author(s):  
Muhammad Hussain Ismail ◽  
Nor Hafiez Mohamad Nor ◽  
Hywel A. Davies ◽  
Iain Todd
Keyword(s):  
Liquid Phase ◽  
Injection Moulding ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Optimum Operating ◽  
Vacuum Furnace ◽  
Major Fraction ◽  
Optimum Operating Condition ◽  
Porous Niti ◽  
Metal Injection Moulding

Porous NiTi alloy with a nearly three-dimensionally interconnected pore structure has been successfully fabricated by a transient liquid phase sintering following the metal injection moulding (MIM) process, using a mixture of Ni and Ti elemental powders. The elemental Ni and Ti powders mixture was mixed with a binder system, comprised mainly polyethylene-glycol (PEG) in an alternative technique using a speed mixer, principally incorporating a dual asymmetric centrifuge (DAC). The powder-binder mixture was then characterized using a capillary rheometer at various temperatures and shear rates. It was found that the feedstock exhibited pseudo-plastic behaviour, which is favourable for the MIM process. A temperature range of 120oC - 130oC was considered as the optimum operating condition for the injection moulding processing. The parts were moulded into cylindrical shapes, leached in warm water (60oC for 10 hours), thermally debound in argon and subsequently sintered in a vacuum furnace at four different temperatures ranging from 950oC to 1250oC.  All samples underwent expansion in both diameter and height after water leaching and sintering.  The XRD results showed that increasing the sintering temperature resulted in a major fraction of the B2 NiTi phase due to phase homogenization and subsequently decreased the amount of secondary phases such as NiTi2 and Ni3Ti. Besides that, the formation of the transient liquid phase during sintering enabled major fraction of pores to be developed with porosity and average size of 39 - 45% and 100 - 120 μm, respectively. The porous parts produced have a great potential to be used as an implant in biomedical applications. 

Porous NiTi alloy by metal injection moulding/sintering of elemental powders: Effect of sintering temperature

2012 ◽  
Vol 70 ◽  
pp. 142-145 ◽  
Author(s):  
Muhammad Hussain Ismail ◽  
Russell Goodall ◽  
Hywel A. Davies ◽  
Iain Todd
Keyword(s):  
Injection Moulding ◽  
Sintering Temperature ◽  
Niti Alloy ◽  
Porous Niti ◽  
Metal Injection Moulding

Transient liquid-phase sintering using silver and tin powder mixture for die bonding

2016 ◽  
Vol 55 (4S) ◽  
pp. 04EC14 ◽  
Author(s):  
Masahisa Fujino ◽  
Hirozumi Narusawa ◽  
Yuzuru Kuramochi ◽  
Eiji Higurashi ◽  
Tadatomo Suga ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Powder Mixture ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Die Bonding ◽  
Transient Liquid Phase Sintering

Microstructure of Transient Liquid Phase Sintering Joint by Sn-Coated Cu Particles for High Temperature Packaging

2015 ◽  
Vol 2015 (1) ◽  
pp. 000449-000452 ◽  
Author(s):  
Xiangdong Liu ◽  
Hiroshi Nishikawa
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Liquid Phase ◽  
Applied Pressure ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Thermally Stable ◽  
Bonding System ◽  
Cu Substrates ◽  
Transient Liquid Phase Sintering

We develop a transient liquid phase sinter (TLPS) bonding using Sn-coated Cu micro-sized particles. With this bonding process, a thermally stable joint comprising Cu3Sn phase and a dispersion of ductile Cu particles can be obtained. The particle paste, which contained Cu particles with a thin Sn coating and terpineol, was used to join Cu substrates. The setup was bonded at 300 °C for 30s under an applied pressure of 10 MPa using a thermo-compression bonding system under a formic acid gas atmosphere for reducing the oxide layer on the Sn coating and the Cu substrate. After bonding, the TLPS joint showed a thermally stable microstructure with a good shear strength, which was fully consisted of Cu3Sn intermetallic compounds matrix and embedded ductile Cu particles. The kinetics of the microstructure transformation and high temperature reliability of the TLPS joint were investigated. After 300 °C isothermal aging for 200h, the shear strength and microstructure of the TLPS joints showed almost unchanged. The results demonstrate that joint with high-melting-point obtained by the TLPS bonding using Sn-coated Cu particle paste has the potential to fulfill the requirement of high temperature electronic packaging.

scholarly journals Transient Liquid Phase Bonding of Ti-6Al-4V and Mg-AZ31 Alloys Using Zn Coatings

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 769 ◽  
Author(s):  
Abdulaziz AlHazaa ◽  
Ibrahim Alhoweml ◽  
Muhammad Shar ◽  
Mahmoud Hezam ◽  
Hany Abdo ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Microstructural Analysis ◽  
Transient Liquid Phase ◽  
Isothermal Solidification ◽  
Uniaxial Pressure ◽  
Transient Liquid Phase Bonding ◽  
Vacuum Furnace ◽  
Joint Region ◽  
Ductile Fractures ◽  
Zinc Coatings

Ti-6Al-4V and Mg-AZ31 were bonded together using the Transient Liquid Phase Bonding Process (TLP) after coating both surfaces with zinc. The zinc coatings were applied using the screen printing process of zinc paste. Successful bonds were obtained in a vacuum furnace at 500 °C and under a uniaxial pressure of 1 MPa using high frequency induction heat sintering furnace (HFIHS). Various bonding times were selected and all gave solid joints. The bonds were successfully achieved at 5, 10, 15, 20, 25, and 30 min. The energy dispersive spectroscopy (EDS) line scan confirmed the diffusion of Zn in both sides but with more diffusion in the Mg side. Diffusion of Mg into the joint region was detected with significant amounts at bonds made for 20 min and above, which indicate that the isothermal solidification was achieved. In addition, Ti and Al from the base alloys were diffused into the joint region. Based on microstructural analysis, the joint mechanism was attributed to the formation of solidified mixture of Mg and Zn at the joint region with a presence of diffused Ti and Al. This conclusion was also supported by structural analysis of the fractured surfaces as well as the analysis across the joint region. The fractured surfaces were analyzed and it was concluded that the fractures occurred within the joint region where ductile fractures were observed. The strength of the joint was evaluated by shear test and found that the maximum shear strength achieved was 30.5 MPa for the bond made at 20 min.

scholarly journals Deformation Behavior of Transient Liquid-Phase Sintered Cu-Solder-Resin Microstructure for Die-Attach

2019 ◽  
Vol 9 (17) ◽  
pp. 3476 ◽  
Author(s):  
Hiroaki Tatsumi ◽  
Hiroshi Yamaguchi ◽  
Tomoki Matsuda ◽  
Tomokazu Sano ◽  
Yoshihiro Kashiba ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Resin Composite ◽  
Copper Substrate ◽  
Transient Liquid Phase ◽  
Liquid Phase Sintering ◽  
Experimental Investigations ◽  
Uniaxial Tensile ◽  
Element Analysis ◽  
Die Attach ◽  
Deformation Properties

We have proposed a low-temperature bonding technology utilizing the sintering of Cu particles with transient liquid-phase of Sn-based solder, called transient liquid-phase sintering (TLPS), as a die-attach solution for high-temperature power modules. A copper-intermetallic compound-resin (Cu-IMC-resin) microstructure, which consists of Cu particles connected with Cu–Sn intermetallic compounds (IMCs) partially filled with polyimide resin, is obtained by the pressureless TLPS process at 250 °C for 1 min using a novel Cu-solder-resin composite as the bonding material in a nitrogen atmosphere. Macro- and micro-deformation properties of the unique microstructure of the TLPS Cu-IMC-resin are evaluated by finite element analysis using a three-dimensional image reconstruction model. The macroscopic computational uniaxial tensile tests of the Cu-IMC-resin model reveal that the utilization of the IMCs and the addition of the easily-deformable resin facilitates the temperature-stability and low-stiffness of the mechanical properties. The microstructure exhibits a significantly low homogenized Young’s modulus (11 GPa). Microscopic investigations show that the local stresses are broadly distributed on the IMC regions under uniaxial macroscopic tensile displacement, indicating highly reliable performance of the joint within a specific macroscopic strain condition. Numerical and experimental investigations demonstrate the excellent thermal cyclic reliability of die-attached joints between silicon carbide chips and directly bonded copper substrate.

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