Introduction to Full Density Powder Metallurgy

2015 ◽  
pp. 253-254
Keyword(s):  
Powder Metallurgy ◽  
Full Density

Ultra-Fine Grained Ti-15Mo Alloy Prepared by Powder Metallurgy

2018 ◽  
Vol 941 ◽  
pp. 1276-1281
Author(s):  
Anna Terynková ◽  
Jiří Kozlík ◽  
Kristína Bartha ◽  
Tomáš Chráska ◽  
Josef Stráský
Keyword(s):  
Powder Metallurgy ◽  
Bulk Material ◽  
Alpha Phase ◽  
Full Density ◽  
Fine Grained ◽  
Cryogenic Milling ◽  
Aircraft Manufacturing ◽  
Plasma Sintering ◽  
Beta Matrix ◽  
Spark Plasma

Ti-15Mo alloy belongs to metastable β-Ti alloys that are currently used in aircraft manufacturing and Ti15Mo alloy is a perspective candidate for the use in medicine thanks to its biotolerant composition. In this study, Ti15Mo alloy was prepared by advanced techniques of powder metallurgy. The powder of gas atomized Ti-15Mo alloy was subjected to cryogenic milling to achieve ultra-fine grained microstructure within the powder particles. Powder was subsequently compacted using spark plasma sintering (SPS). The effect of cryogenic milling on the microstructure and phase composition of final bulk material after SPS was studied by scanning electron microscopy. Sintering at 750°C was not sufficient for achieving full density in gas atomized powder, while milled material could be successfully sintered at this temperature. Alpha phase particles precipitated during sintering and their size, as well as the size of beta matrix grains, was strongly affected by the sintering temperature.

Processing and Mechanical Properties of Solid Core and Porous Surface Ti-6Al-4V Implants Fabricated by Powder-Metallurgy

2007 ◽  
Vol 345-346 ◽  
pp. 1209-1212
Author(s):  
Montasser Dewidar ◽  
Jae Kyoo Lim
Keyword(s):  
Powder Metallurgy ◽  
Inner Core ◽  
Porous Surface ◽  
Full Density ◽  
Compressive Yield Strength ◽  
Solid Core ◽  
Heavy Load ◽  
Human Teeth ◽  
Joint Replacements ◽  
Porous Ti

Porous-surfaced with solid core Ti-6Al-4V implant compacts were fabricated by traditional powder metallurgy. Powder metallurgy technique was used to produce three different porous surfaced implant compacts 30, 50, and 70% in vacuum atmosphere. The solid core formed in the center of the compact shows similar microstructure of near full density of Ti-6Al-4V. The compressive yield strength was up to 270 MPa and significantly depended on the surface porosity, core size, and temperature of sintering. Selected porous-surfaced Ti-6Al-4V implant compacts with a solid core have much higher compressive strengths compared to the human teeth and sintered fully porous Ti-6Al-4V joint replacements. The ingrowth of bone tissue into the outer porous surface layer results in part fixation, while the solid inner core region provides the necessary mechanical strength for a device used for the replacement of heavy load bearing joint regions such as the hip and knee. The microstructure of sintered samples was investigated.

scholarly journals Manufacturing full density powder metallurgy gears through HIP:ing

2019 ◽  
Vol 74 (4) ◽  
pp. 199-203
Author(s):  
Michael Andersson ◽  
Magnus Bergendahl ◽  
Ulf Bjarre ◽  
Anders Eklund ◽  
Staffan Gunnarsson ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Full Density

Effect of Carbon Addition on the Microstructure and Properties of M3:2 High Speed Steels Processed by Powder Metallurgy

2007 ◽  
Vol 29-30 ◽  
pp. 153-158 ◽  
Author(s):  
R. Zhou ◽  
D. Wang ◽  
Jun Shen ◽  
J. Sun
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Oxygen Content ◽  
High Speed ◽  
Sintering Temperature ◽  
Experimental Results ◽  
Full Density ◽  
Bend Strength ◽  
Carbon Addition ◽  
Sintered Steels

M3:2 high speed steels with and without carbon addition were prepared by using powder metallurgy at sintering temperature between 1210 and 1280 °C. Densification, microstructure and mechanical properties of M3:2 high speed steels were investigated. Experimental results show that with 0.4wt% carbon addition, full density high speed steels were obtained at temperatures in the range 1240-1260 °C which is 40 °C lower than that of the undoped counterparts, leading to a sintering window expanded by 10 to 20 °C. By the addition of 0.4wt% carbon, the sintered steels show attractive combinations of bend strength and hardness over those of M3:2 steels without carbon addition. The results reveal that the addition of carbon will not only lower the sintering temperature and oxygen content, but also improve the mechanical properties of the sintered steels.

Effect of Zn on Microstructure and Mechanical Properties of Al-Zn-Mg-Cu-Zr Alloy by Powder Metallurgy

2013 ◽  
Vol 710 ◽  
pp. 102-105
Author(s):  
Chuan Dong Wu ◽  
Cheng Zhang Li ◽  
Pan Fang ◽  
Guo Qiang Luo ◽  
Qiang Shen
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Powder Metallurgy ◽  
Full Density ◽  
Hot Press ◽  
X Ray Diffraction ◽  
Electron Probe Micro Analyzer ◽  
Microstructure And Mechanical Properties ◽  
Hot Press Sintering ◽  
Zr Alloy

In this paper, full-density Al-Zn-Mg-Cu-Zr powder metallurgy (P/M) alloy is prepared by hot-press sintering in vacuum at 600°C. Experiments are conducted to evaluate the effects of Zn additive in the range of 7.2-8.4 wt.% on the microstructure and mechanical properties of Al-Zn-Mg-Cu-Zr alloys. X-ray diffraction (XRD), scanning electron microstructure (SEM) and electron probe micro-analyzer (EPMA), and mechanical properties such as tensile strength are measured. The porosity decreases gradually with increasing of Zn and it achieves 0.01% with a density of 2.95 g/cm3 at 8.4% Zn. The tensile strength reaches the maximal value of 436 MPa at 8.4% Zn.

A Comparative Study on the Sintering and Casting of a Blended Elemental Ti-6Al-4V Alloy

2015 ◽  
Vol 828-829 ◽  
pp. 421-426
Author(s):  
Muziwenhlanhla A. Masikane ◽  
Hilda K. Chikwanda ◽  
Iakovos Sigalas
Keyword(s):  
Powder Metallurgy ◽  
Chemical Composition ◽  
Cast Alloy ◽  
Full Density ◽  
Interstitial Oxygen ◽  
High Concentration ◽  
Blended Elemental ◽  
Lower Oxygen ◽  
Cast Alloys ◽  
The Cost

Over the past years, the blended elemental powder metallurgy (PM) approach has been identified as one of the most promising strategies to reduce the cost of titanium-based components. However, oxygen pick-up, inhomogeneity of the microstructure and chemical composition are sometimes reported for PM parts. This work compares properties of a blended elemental Ti-6Al-4V alloy obtained by sintering under argon gas atmosphere with those of a vacuum cast alloy. Argon was purified by passing it through a series of oxygen and moisture traps prior to being introduced into the sintering furnace. Casting was performed under vacuum (1 x 10-3 mbar). The starting material in both processes was the cold isostaticaly pressed blended elemental (BE) Ti-6Al-4V powder compact. The BE powder was prepared by mixing 60Al-40V master alloy powder with commercial Grade 4 titanium powder (0.377 wt.% O2). The sintered and cast alloys were compared on the basis of oxygen pick-up, density, microstructure, chemical composition and hardness to determine which method is better. Although the BE approach could not eliminate the common challenges associated with powder metallurgy processing of Ti alloys, oxygen pick-up and additional contamination was lower compared vacuum casting. Sintering at 1350°C for 1 h could not achieve full density compared to casting, but the microstructure appeared more homogeneous. Both sintered and cast Ti6Al4V alloys were harder than wrought Ti6Al4V due to a high concentration of interstitial oxygen. The sinterered and sintered plus HIPed Ti6Al4V alloys were softer than as-cast Ti6Al4V due to lower oxygen pick-up and incomplete densification. From the contamination and homogeneity perspective, the BE approach is an attractive technique for processing of Ti6Al4V alloy.

Mechanical Properties of Oxide Dispersion Strengthened Pure Titanium Produced by Powder Metallurgy Method

2010 ◽  
Vol 654-656 ◽  
pp. 815-818 ◽  
Author(s):  
Tomohito Yoshimura ◽  
Thotsaphon Thrirujirapaphong ◽  
Hisashi Imai ◽  
Katsuyoshi Kondoh
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
High Performance ◽  
Pure Titanium ◽  
Full Density ◽  
Powder Metallurgy Method ◽  
Oxide Dispersion ◽  
Dispersion Strengthening ◽  
Tio2 Particles ◽  
Material Cost

Pure titanium has good specific properties i.e. low density of 4.5g/cm3, extremely high resistance for corrosion and good elongation. However, its mechanical properties are not enough to be employed as structural parts and components. Accordingly, titanium alloys are often applied to industrial fields due to their high specific strength. However, the application is limited to high-performance products because of their expensive material cost and poor plastic formability at low temperature. In the present study, from a view point of cost reduction, pure titanium was used as a starting material. The materials design by oxide dispersion strengthening (ODS) was basically applied to improve the poor mechanical strength of pure titanium. TiO2 powders were used as reinforcement dispersoids because of their easily obtainable and low material cost. Powder metallurgy (P/M) method was applied to fabricate TiO2 particles reinforced pure titanium composite. Pure titanium powder and TiO2 particles were elementally mixed by conventional mixing process. Their elemental mixture powders were consolidated by using spark plasma sintering (SPS) equipment to serve a high density compact billet. Subsequently, hot extrusion process was applied to the billet to prepare a full density rod specimen. The evaluation of mechanical properties at room temperature showed high tensile strength of 1040 MPa and good elongation of 25 % when the composite included 1.5mass% TiO2 particles.

Amorphous silica coating on α-alumina particles

1995 ◽  
Vol 53 ◽  
pp. 210-211
Author(s):  
J. W. Mellowes ◽  
C. M. Chun ◽  
I. A. Aksay
Keyword(s):  
Amorphous Silica ◽  
Heterogeneous Nucleation ◽  
Homogeneous Nucleation ◽  
Silica Coating ◽  
Full Density ◽  
Optimal Conditions ◽  
Fine Grained ◽  
Alumina Particles ◽  
Complete Mullitization ◽  
Powder Compacts

Mullite (3Al2O32SiO2) can be fabricated by transient viscous sintering using composite particles which consist of inner cores of a-alumina and outer coatings of amorphous silica. Powder compacts prepared with these particles are sintered to almost full density at relatively low temperatures (~1300°C) and converted to dense, fine-grained mullite at higher temperatures (>1500°C) by reaction between the alumina core and the silica coating. In order to achieve complete mullitization, optimal conditions for coating alumina particles with amorphous silica must be achieved. Formation of amorphous silica can occur in solution (homogeneous nucleation) or on the surface of alumina (heterogeneous nucleation) depending on the degree of supersaturation of the solvent in which the particles are immersed. Successful coating of silica on alumina occurs when heterogeneous nucleation is promoted and homogeneous nucleation is suppressed. Therefore, one key to successful coating is an understanding of the factors such as pH and concentration that control silica nucleation in aqueous solutions. In the current work, we use TEM to determine the optimal conditions of this processing.

Microstructural and fractographic characterization of B4C-Al cermets tested under dynamic and static loading

1989 ◽  
Vol 47 ◽  
pp. 562-563
Author(s):  
Gyeung Ho Kim ◽  
Mehmet Sarikaya ◽  
D. L. Milius ◽  
I. A. Aksay
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Fracture Toughness ◽  
Static Loading ◽  
Carbon Deposition ◽  
Full Density ◽  
Unique Combination ◽  
Strong Component ◽  
Reaction Products

Cermets are designed to optimize the mechanical properties of ceramics (hard and strong component) and metals (ductile and tough component) into one system. However, the processing of such systems is a problem in obtaining fully dense composite without deleterious reaction products. In the lightweight (2.65 g/cc) B4C-Al cermet, many of the processing problems have been circumvented. It is now possible to process fully dense B4C-Al cermet with tailored microstructures and achieve unique combination of mechanical properties (fracture strength of over 600 MPa and fracture toughness of 12 MPa-m1/2). In this paper, microstructure and fractography of B4C-Al cermets, tested under dynamic and static loading conditions, are described.The cermet is prepared by infiltration of Al at 1150°C into partially sintered B4C compact under vacuum to full density. Fracture surface replicas were prepared by using cellulose acetate and thin-film carbon deposition. Samples were observed with a Philips 3000 at 100 kV.

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