We like to take this opportunity to rectify an error in the schematic drawing in two of our recently published research articles. A typographical error of a number appeared in Fig. 5 of J. Mater. Res. 20, 2225 (2005), p. 2229 and in Fig. 2 of J. Mater. Res. 21, 947 (2006), p. 948: these two figures are the same schematic drawing. In both figures, the number “1” on the slopes should be changed to “2.” The correct figure is given as Fig. 1 in this erratum.

Diffusion bonding of Ti3SiC2 and nickel has been conducted at temperatures of 800 °C–1100 °C for 10–90 min under 6–20 MPa in a vacuum. The phase composition and microstructure of the joints were investigated by X-ray diffraction, scanning electron microscopy, and electron probe microanalysis. The total diffusion path of the joining is determined to be Ni/Ni31Si12 + Ni16Ti6Si7 + TiCx/Ti3SiC2 + Ti2Ni + TiCx/ Ti3SiC2. The growth of the reaction layer follows parabolic law, and the temperature dependence of the reaction constant, k, can be expressed as k = 1.68 × 10−4 exp(−118 ± 12 kJ/RT) m/s1/2. The diffusion of nickel through the reaction zone toward Ti3SiC2 is the main controlling step in the bonding process. Joint strengths were determined through shear tests. The maximum shear strength of 121 ± 7 MPa, which is close to the shear strength of Ti3SiC2, has been obtained under the condition of 1000 °C for 10 min under 20 MPa.

The purpose of this erratum is to correct the omission of a coauthor, Joshua C. Falkner, Department of Chemistry, Rice University, Houston, Texas.

Bond coats play a crucial role in the performance of thermal barrier coating systems. Ru alloys have been identified as promising candidates; therefore, systematic studies were performed on the oxidation behavior of bulk RuAl (50–50 at.%). Isothermal oxidation and thermogravimetric analyses were performed at 1100 °C for different times ranging from 0.1 h to 500 h. Microstructural characterization was performed by scanning and transmission electron microscopy. The results showed the formation of an α–Al2O3 layer on top of a δ–Ru layer. Interface instability between these layers and evaporation of gaseous Ru-oxides lead to the formation of large elongated cavities and alternating α–Al2O3/δ–Ru layers.

There has been much recent interest in heat transport in nanostructures, and alsoin the structure, properties, and growth of biological materials. Here we present measurements of thermal properties of a nanostructured biomineral, ivory. The room-temperature thermal conductivity of ivory is anomalously low in comparison with its constituent components. Low-temperature (2–300 K) measurements ofthermal conductivity and heat capacity reveal a glass-like temperature dependenceof the thermal conductivity and phonon mean free path, consistent with increased phonon-boundary scattering associated with nanostructure. These results suggest that biomineral-like nanocomposite structures could be useful in the design of novel high-strength materials for low thermal conductivity applications.

We have connected viscoelastic recovery (healing) in sliding wear to free volume in polymers by using pressure-volume-temperature (P-V-T) results and the Hartmann equation of state. A linear relationship was found for all polymers studied with a wide variety of chemical structures, except for polystyrene (PS). Examination of the effect of the indenter force level applied in sliding wear on the healing shows that recovery is practically independent of that level. Strain hardening in sliding wear was observed for all materials except PS, the exception attributed to brittleness. Therefore, we have formulated a quantitative definition of brittleness in terms of elongation at break and storage modulus. Further, we provide a formula relating the brittleness to sliding wear recovery; the formula is obeyed with high accuracy by all materials including PS. High recovery values correspond to low brittleness, and vice versa. Our definition of brittleness can be used as a design criterion for choosing polymers for specific applications.

In this paper, we demonstrate that films of magnetite, Fe3O4, can be deposited by the electrochemical reduction of a Fe(III)-triethanolamine complex in aqueous alkaline solution. The films were deposited with a columnar microstructure and a [100] preferred orientation on stainless steel substrates. In-plane electrical transport and magnetoresistance measurements were performed on the films after they were stripped off onto glass substrates. The resistance of the films was dependent on the oxygen partial pressure. We attribute the increase in resistance in O2 and the decrease in resistance in Ar to the oxidation and reduction of grain boundaries. The decrease in resistance in an Ar atmosphere exhibited first-order kinetics, with an activation energy of 0.2 eV. The temperature dependence of the resistance showed a linear dependence of log(R) versus T−1/2, consistent with tunneling across resistive grain boundaries. A room-temperature magnetoresistance of −6.5% was observed at a magnetic field of 9 T.

Based on a comparison of relationships between energy dissipated during indentation and the ratio of hardness to reduced elastic modulus, Malzbender has recently proposed a procedure to determine both hardness and elastic modulus from a single loading–unloading indentation curve. However, a more accurate analysis of this relationship shows that, in fact, it suffers from the same limitations as the well-known Oliver and Pharr's method; i.e., in general, the true projected imprint area has to be measured in addition to the load–penetration curve or at least two such curves obtained with different indenter geometries are to be used to unequivocally determine the hardness and the elastic modulus of a material.