Si-Containing Beta Titanium Alloy Grain Refinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current β-type titanium alloys produced by casting or plastic forming methods result in coarse grain sizes, leading to lower strength, poor wear resistance, and brittleness, which are unsuitable for medical applications due to the continuous grain boundary phase's detrimental effects on mechanical properties.
Innovation Solution
A method involving alloy composition design with specific atomic percentages of Ti, Nb, Zr, Ta, and Si, followed by high-temperature plastic deformation and recrystallization annealing, to achieve a high-strength and low-modulus β-type Si-containing titanium alloy with refined microstructure and improved biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If casting or plastic forming method is used to prepare β-type titanium alloy, then the production process is simple, but the grain size becomes coarse (at least 40 to 60 μm or more) resulting in lower strength and poor wear resistance
Solution Approach 1:
The patent applies preliminary action by performing high-temperature plastic deformation (hot rolling) at 800-900°C before final cooling. This pre-deformation step creates a refined microstructure and distributes alloying elements uniformly, which subsequently enables the material to achieve fine grain structure after cooling, thereby resolving the contradiction between simple production process and high strength requirements
Solution Approach 2:
The patent changes key process parameters including deformation temperature (800-900°C), deformation amount (60-80%), and cooling rate to achieve grain refinement. By optimizing these parameters, the alloy transforms from coarse-grained structure after casting to fine-grained structure with improved strength while maintaining relatively simple production process
2Adaptability or versatility
If non-metallic element Si is introduced to enhance controllability and form metal compounds, then the performance regulation capability is improved, but continuous Si-containing grain boundary phase forms causing brittleness and poor plasticity
Solution Approach 1:
The patent applies segmentation by introducing Al element that forms Al-rich phases at grain boundaries, which segment and interrupt the continuous Si-containing brittle phase. This segmentation breaks the harmful continuous network structure into discrete particles, eliminating the brittleness caused by continuous grain boundary phase while preserving the performance regulation capability of Si addition
Solution Approach 2:
The patent uses Al element as an intermediary that mediates between Si addition and grain boundary structure. Al acts as a buffer that prevents direct formation of continuous Si-rich brittle phases, instead forming Al-containing phases that maintain grain boundary integrity while allowing Si to contribute to overall alloy performance enhancement
3Ease of manufacture
If coarse grain size structure is obtained from casting method, then the processing is easier, but the biocompatibility and osteoclast adhesion are reduced
Solution Approach 1:
The patent performs high-temperature plastic deformation as a preliminary action before final cooling and solidification. This pre-deformation step establishes a refined microstructure framework that is subsequently locked in during cooling, achieving fine grain size (5-50 μm) without requiring complex post-processing, thus maintaining processing ease while improving biocompatibility
Solution Approach 2:
The patent changes the temperature parameter during processing (heating to 800-900°C for deformation, then water quenching) to control grain growth. By precisely controlling these thermal parameters, the alloy achieves fine grain structure that enhances osteoclast adhesion and biocompatibility while keeping the overall processing flow relatively simple
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively refines the grain structure, enhancing strength and plasticity while reducing modulus of elasticity, making the alloy more suitable for biomedical applications by overcoming the limitations of continuous grain boundary phases.
Implementation Method 1
high temperature plastic deformation: subjecting the resulting ingot obtained in step (2) to high temperature plastic deformation with a deformation temperature of 800-900° C. and a deformation rate of 60-80%
Implementation Method 2
recrystallization: heating the resulting test sample in step (3) to a recrystallization temperature, maintaining the temperature for 1-4 h, and carrying out an annealing treatment
Data Source
AI summary
A preparation method for high-strength and low-modulus β-type Si-containing titanium alloy involves: preparing an alloy component with, in atomic percentage, 60-70% of Ti, 10-20% of Nb, 5-15% of Zr, 1-10% of Ta and 1-5% of Si and using sponge titanium, sponge zirconium, a tantalum-niobium intermediate alloy and silicon as raw materials, and then uniformly smelting the alloy components to obtain a solidified ingot; then, subjecting the resulting ingot to plastic deformation with a deformation temperature of 800-900° C. and a deformation rate of 60-80%, and water-quenching same to room temperature; and finally, heating the resulting test sample to a recrystallization temperature, maintaining the temperature for 1-4 h, and carrying out an annealing treatment and air-cooling same to room temperature to obtain the high-strength and low-modulus β-type Si-containing titanium alloy. The resulting titanium alloy is more suitable for use as a medical implant material.