Joining of Zirconia Reinforced Metal–Matrix Composites by a Ceramics‐Derived Technology

Abstract

Metal-matrix composites composed of an austenitic stainless steel and magnesia partially stabilized zirconia were prepared via a powder metallurgical processing route with the ceramics-derived extrusion at room temperature. Various combinations of the base materials with zirconia volume fractions of 0, 5, and 10% were joined by applying an aqueous paste which forms the joint during thermal processing. The materials were tested under tensile loading at room temperature. The addition of zirconia particles led to a considerable decrease of the plasticity and ultimate tensile strength of the basic compositions. However, the strength of joint specimens was not limited by the bonding strength of the joining zone. Among all material combinations tested, failure occurred in the joining partner with the higher zirconia volume fraction and not at the joint interface. Thus, the strength of sinter-joined materials based on MMC with 0-10 vol% was limited by the strength of the base materials. The advance of the present sinter-joining method is the single thermal operation of the composite materials. The formation of a homogeneous bonding zone and the absence of a heataffected zone lead to negligible interference with the microstructure and the mechanical properties of the base materials.

Metal‐Matrix Materials for High‐Temperature Applications with Liquid Aluminum

“…The interactions are the result of an intensive diffusion of the steel alloying elements and oxygen and of the reaction with the ceramic components during sintering . These mechanisms are widely known from MMC materials with additions of zirconia or alumina with the intensive formation of spinel or silicate structures . Yet, the low Si concentrations in the used powders are assumed to limit the silicate formation to a not adequately measurable quantity.…”

“…[36,38] These mechanisms are widely known from MMC materials with additions of zirconia or alumina with the intensive formation of spinel or silicate structures. [6,18,[40][41][42] Yet, the low Si concentrations in the used powders are assumed to limit the silicate formation to a not adequately measurable quantity. It must be considered that the oxygen quantification by EDS is inaccurate and involves large errors, preventing reliable stoichiometric calculations of the chemistry.…”

Deformation Behavior of Particle Reinforced TRIP Steel/MgPSZ Composite at Hot Working Temperatures

“…Incompatibilities in deformation between the soft metal matrix and the hard particles in turn lead to a decrease in deformability . Moreover, stress concentrations at the particle‐matrix interfaces cause internal damage, particularly particle fracture, and debonding . This behavior is even more amplified by non‐uniform particle distribution and the occurrence of particle clusters …”

“…[8][9][10][11] Moreover, stress concentrations at the particle-matrix interfaces cause internal damage, particularly particle fracture, and debonding. [8,[12][13][14] This behavior is even more amplified by non-uniform particle distribution and the occurrence of particle clusters. [6,15] Regarding the workability and forming behavior, the following conclusions can be drawn.…”

Forming Complex Graded and Homogeneous Components by Joining Simple Presintered Parts of TRIP-Matrix Composite through Powder Forging

“…Hence, they are suitable for use in a range of applications, owing to their higher stiffness, improved strength, which is accompanied by a marginal loss in ductility, and greater wear resistance as compared with those of the unreinforced metal [17][18][19]. In particular, composites based on high-energy-absorbing transformation-induced plasticity (TRIP)/twinning-induced plasticity steels and transformable zirconia (ZrO 2 ) particles show great potential [20][21][22][23]. For instance, reinforcement with MgO-partially stabilized zirconia (Mg-PSZ) particles can increase the strength as well as the wear properties of these composites, owing to the ability of Mg-PSZ to undergo a stress-induced transformation from the tetragonal phase to the monoclinic phase [24][25][26].…”