Powder Consolidation of Titanium and Titanium Alloys by a Powder Compact Forging Process

2016 ◽  
Vol 704 ◽  
pp. 68-74 ◽  
Author(s):  
Ming Tu Jia ◽  
Brian Gabbitas
Keyword(s):  
Mechanical Properties ◽  
Powder Compact ◽  
Titanium Powder ◽  
Full Density ◽  
Low Oxygen ◽  
Powder Consolidation ◽  
Forging Process ◽  
Cp Ti ◽  
Field Assisted Sintering ◽  
Powder Compacts

Powder compact forging in combination with induction sintering, a field assisted sintering technique (FAST), was used to produce commercially pure (CP) Ti and Ti-13V-11Cr-3Al parts. Green powder compacts with high relative density were manufactured by cold compaction and warm compaction, respectively. During the powder compact forging process, CP titanium powder was consolidated completely to produce a near net shaped top cover for a diving helmet with full density and good mechanical properties. Also, a Ti-13V-11Cr-3Al alloy was fully consolidated into a cylinder using blended elemental powders. As a comparison, raw titanium powder with different oxygen contents was used to make a Ti-13V-11Cr-3Al powder compact forging. Using a starting powder with low oxygen content, a forged cylinder with good mechanical properties was produced.

MICROSTRUCTURES AND MECHANICAL PROPERTIES OF ULTRAFINE GRAINED Ti-47Al-2Cr (at %) ALLOY PRODUCED USING POWDER COMPACT FORGING

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1739-1744
Author(s):  
VIJAY N. NADAKUDURU ◽  
DELIANG ZHANG ◽  
PENG CAO ◽  
BRIAN GABBITTAS
Keyword(s):  
Mechanical Properties ◽  
Powder Compact ◽  
High Energy ◽  
Alloy Sample ◽  
Bulk Alloy ◽  
Porosity Level ◽  
Fine Grain ◽  
Ultrafine Grained ◽  
Powder Compacts ◽  
Innovative Techniques

Development of innovative techniques to produce gamma TiAl based alloys, with good mechanical properties, while still maintaining ultra fine grain size can be rewarding, but also is a great challenge. In the present study study a Ti -47 Al -2 Cr ( at %) alloy has been synthesized by directly forging green powder compacts of a Ti / Al / Cr composite powder produced by high energy mechanical milling of a mixture of elemental Ti , Al , Cr powders. It has been found that the density of the bulk consolidated alloy sample after forging decreases from 95% of the theoretical density in the central region to 84% in the periphery region. The microstructure of the bulk alloy consisted of several Ti rich regions, which was expected to be mainly due to initial powder condition. The room temperature tensile strength of the samples produced from this process was found to be in the range of 115 – 130 MPa. The roles of canning and green powder compact density in determining the forged sample porosity level and distribution are discussed.

Consolidation of Titanium, and Ti-6Al-4V Alloy Powders by Powder Compact Forging

2009 ◽  
Vol 618-619 ◽  
pp. 513-516 ◽  
Author(s):  
De Liang Zhang ◽  
Stella Raynova ◽  
Vijay Nadakuduru ◽  
Peng Cao ◽  
Brian Gabbitas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloy ◽  
Powder Compact ◽  
Materials Science ◽  
Value Added ◽  
Cost Effective ◽  
Porosity Level ◽  
Open Die Forging ◽  
Powder Compacts ◽  
Limited Depth

Consolidation of titanium and titanium alloy powders using thermomechanical powder metallurgy (TPM) processes (powder compact forging, extrusion and rolling) is one way that can lead to cost-effective production of high value-added consolidated titanium and titanium alloy products such as near-net shaped components, tubes and plates. This paper provides an overview of the quality, microstructure (to limited depth), porosity level and mechanical properties of disks produced using open die forging of powder compacts of CP titanium and Ti-6Al-4V alloy powders. The general materials science principles underlying the relationships between processing conditions, microstructure and the mechanical properties of the disks made by using the powder compact forging are discussed.

Preparation of Ti-5553 Alloy by Different Extrusion Processes from Elemental Powder Mixtures

2018 ◽  
Vol 770 ◽  
pp. 31-38 ◽  
Author(s):  
Fei Yang ◽  
Brian Gabbitas ◽  
Stiliana Raynova ◽  
Ajit Pal Singh ◽  
Leandro Bolzoni
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Titanium Alloy ◽  
Master Alloy ◽  
Powder Compact ◽  
Titanium Powder ◽  
Mechanical Test ◽  
High Strength ◽  
Powder Mixtures ◽  
Good Ductility

Ti-5553 (Ti-5Al-5V-5Mo-3Cr, wt. %) alloy is a recently developed near β titanium alloy and it has a very good hardenability, good ductility and high strength. In this study, we discussed the feasibility of preparing Ti-5553 alloy by different processes from powder mixtures of hydride-dehydride titanium powder, elemental powders and master alloy powders, including (1) direct extrusion of powder compact in argon, (2) extrusion of the vacuum-sintered billet in air and (3) extrusion of the hot-pressed billet in air. XRD, OM and SEM were used to determine the phase constitutions and microstructures of the prepared Ti-5553 alloys, and mechanical test was performed to examine their mechanical properties. The results showed the microstructures and phase constitutions of Ti-5553 alloys were significantly affected by different processes, which resulted in the relevant mechanical properties. The effect of the selected heat treatment on the microstructures and properties of Ti-5553 alloy were investigated as well.

Sintering of Titanium Powder Compacts for Containerless Hot Isostatic Pressing

2009 ◽  
Vol 618-619 ◽  
pp. 509-512 ◽  
Author(s):  
Ray J. Low ◽  
Ian M. Robertson ◽  
Ma Qian ◽  
Graham B. Schaffer
Keyword(s):  
Liquid Phase ◽  
Titanium Powder ◽  
Hot Isostatic Pressing ◽  
Cost Effective ◽  
Liquid Phase Sintering ◽  
Full Density ◽  
Isostatic Pressing ◽  
Surface Densification ◽  
Powder Compacts ◽  
Made In

The liquid-phase sintering of Ti-Si binary alloys using mixed elemental powders has been explored. Sintering at low liquid contents avoids excessive porosity and bulging of compacts, and leads to development of a densified surface. Compacts made in this way can be HIPped without a container to full or near full densities. Exploiting the surface densification phenomenon may enable cost-effective net shape manufacturing of full density titanium components.

Tensile Properties and Fracture Behaviour of Induction Sintered Ti and Ti-6Al-4V (wt %) Powder Compacts

2011 ◽  
Vol 275 ◽  
pp. 196-199 ◽  
Author(s):  
Stella Raynova ◽  
De Liang Zhang ◽  
D. Polo ◽  
L. Gonthier ◽  
W. Egea ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Tensile Properties ◽  
Metal Powder ◽  
Induction Heating ◽  
Diffusion Bonding ◽  
Powder Compact ◽  
Fracture Behaviour ◽  
Powder Consolidation ◽  
Sintered Powder ◽  
Powder Compacts

Induction heating of powder compacts could be a very effective method for metal powder consolidation to get the final product or as an intermediate consolidation step to produce feedstock for metal powder forging or extrusion. Our study has proven that only a few minutes of induction heating, of Ti and Ti-6Al-4V (wt %) powder compacts, increases their density dramatically and causes a significant sintering effect, as evidenced by the formation of interparticle diffusion bonding and reflected by the tensile properties of the induction sintered powder compacts. This paper presents and discusses the results of a study on the tensile properties and fracture behaviour of the Ti and Ti-6Al-4V powder compacts sintered under a variety of induction heating conditions. Keywords: Titanium alloys, powder consolidation, powder compact sintering, induction heating.

scholarly journals Effect of Direct Powder Forging Process on the Mechanical Properties and Microstructural of Ti-6Al-4V ELI

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4499
Author(s):  
Sébastien Germain Careau ◽  
Bernard Tougas ◽  
Elena Ulate-Kolitsky
Keyword(s):  
Mechanical Properties ◽  
Titanium Powder ◽  
Rolling Process ◽  
Industrial Applications ◽  
Thermomechanical Process ◽  
Forging Process ◽  
Β Phase ◽  
Open Die Forging ◽  
Promising Avenue ◽  
Large Spherical

The study of powder metallurgy processing methods for titanium represents a promising avenue that can respond to a growing demand. This work reports the feasibility of direct powder forging (DPF) as a method to process large spherical Ti-6Al-4V powder into wrought products with noteworthy properties and physical characteristics. Direct powder forging is a thermomechanical process that imparts uniaxial loading to an enclosed and uncompacted powder to produce parts of various sizes and shapes. Stainless steel canisters were filled with prealloyed Ti-6Al-4V powder and consolidated through a multi-step open-die forging and rolling process into wrought DPF bars. After DPF, annealing was performed in the upper α+β phase. The results show that full consolidation was achieved and higher mechanical properties than the Ti-6Al-4V grade F-23 requirements in annealed conditions were obtained. The results also show that direct powder forging of spherical titanium powder could produce wrought mill products and exhibit some potential for further investigation for industrial applications.

Densification Study of Titanium Powder Compacts

2005 ◽  
Vol 498-499 ◽  
pp. 211-216 ◽  
Author(s):  
Márcia Christina Carneiro Ueta ◽  
Carlos Augusto Fracote ◽  
Vinicius André Rodrigues Henriques ◽  
Mario Lima de Alencastro Graça ◽  
Carlos Alberto Alves Cairo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Ball Mill ◽  
Titanium Powder ◽  
Titanium Sponge ◽  
Kroll Process ◽  
Titanium Powders ◽  
Powder Compacts ◽  
Scanning Electron

Powder compaction characteristics is a very important parameter to control in order to obtain products with best mechanical properties made by P/M techniques. This work presents a study on the densification of titanium powders trying to optimize the particle size distribution for the best packing and the maximum densification by pressure compaction. The powders used were made from titanium sponge obtained by the Kroll process. The powders were embrittled by mean of the Hydride-Dehydride process (HDH) and milled in a rotative ball-mill under vacuum. Powders with different particles sizes distributions were mixed in several proportions according to Alfred's and Andreasen’s Theory. The samples were compacted by uniaxial and isostatic pressing and sintered under vacuum. The evaluation of the densification was made following the Standard method of test for density of glass by Buoyancy (ASTM – C693-74) and by scanning electron microscopy (SEM). The samples made with powder milled during 36 hours and 12 hours presented better densification than the ones milled during shorter time and the ones with distributions combinations.

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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