Possibility of As-Cast Applications on β-Type Titanium Alloys Proposed in the Newly Expanded Area of <i>Bo_t-Md_t</i> Diagram

Abstract

Ten types ¢-type titanium alloys for as-cast applications were proposed by using mainly ubiquitous elements in the area greatly differ from conventional alloys in compositions, in the diagram consisting of bond order (Bo) and d-orbital energy level (Md). The object was to develop ¢type titanium alloys with ultimate tensile strength value of 1000 MPa and fracture strain value of 10% in as-cast condition without the posttreatments after cold crucible levitation melting, and their microstructures were controlled by adjusting its process parameters. The same microstructure and mechanical properties were also indicated on both as-cast and solution treated alloys, which mean the unnecessary of solution treatment in proposed alloys. Ti5.2Cr5.5Mn2.2Fe5.5Zr, Ti11Cr6Mn4.5Zr0.5Al and Ti13Zr6Mn6Cr5V alloys with a ¢ mono phase achieved objective values of mechanical properties in as-cast condition, which lead to development of alternative materials to the conventional ¢type titanium alloys, since they reduce energy consumption and 25% production costs by omitting complex post processing procedures. Moreover, the phase boundary between the mono ¢ phase and dual ¢ plus intermetallic compound phases were predicted for the first time in ¢type titanium alloys, according to the ten proposed alloys in newly expanded compositional area of the Bo t -Md t diagram.

Study of Electrochemical and Biological Characteristics of As-Cast Ti-Nb-Zr-Ta System Based on Its Microstructure

“…Different as-cast materials have been studied for biomedical applications as Ti-12Mo-xNb, with non-post processing procedures that were investigated for the effect of Nb content on β-Ti alloy in hardness, and the elastic modulus related to the β phase content [12]. In the work of Ma et al, 2021, different β-Ti alloys fabricated by as-cast omitting post processing procedures to reduce costs production [13] were studied, as well as in the work of Rodrigues et al, 2021, which studied a novel as-cast Ti-Mo-Zr alloy with high β phase content, also for biomedical application [14]. However, there is a lack of electrochemical information about the as-cast β-Ti alloys with non-post processing procedures.…”

Design of Near α-Ti Alloys with Optimized Mechanical and Corrosion Properties and Their Characterizations

“…Impurities or contaminants from the crucible and/or atmosphere would greatly affect the mechanical properties of Ti alloys [9,10]. Cold Crucible Levitation Melting (CCLM) technology offered an effective means of preventing contaminants from the crucible and efficiently managing the vacuum within the furnace [11,12]. The molten metals were raised by the eddy current of CCLM and were melted without contact with the crucible.…”

The Effect of IMCs and Segregation on the Microstructure and Mechanical Properties of β-Type Titanium Alloys

“…Some approaches were carried out by researchers to reduce the cost of β-Ti alloys, such as the development of β-Ti alloys with cheap alloying elements and the proposal of β-Ti alloys with simplified post-treatment procedures [8,9]. Solid solution strengthening is also a possible approach to improve the mechanical properties of β-Ti alloys by adding a high content of alloying elements [10,11]. The super-plasticity performance and tensile properties of Ti alloys were enhanced by optimizing their compositions with Ni and Co alloying elements [12].…”

“…Therefore, the discussion and identification of the influence of IMCs and segregation behaviors in multi-component β-Ti alloys is important and meaningful. The occurrence of IMCs could be approximately predicted using the d-orbital energy level (Md t ) and the bond-order (Bo t ) parameters based on the positions of alloys in the Md t -Bo t diagram [10].…”

“…High-temperature alpha-type alloys, high-strength beta-type alloys, and high-corrosion-resistance alloys have been developed by considering their Bo and Md values and positions in the Md t -Bo t diagram [29]. The adaptation of the d-electrons concept could be used to design new composition β-Ti alloys conveniently and effectively at a reduced cost [10,28,30]. The Md t -Bo t diagram was widely used to predict the chemical properties, deformation types and mechanical properties of β-Ti alloys [1,11].…”