1.Overview

Biomedical materials are an important branch of materials science,used for diagnosing,treating,or replacing human tissues and organs,or enhancing their functions.They are new carrier materials with high technological content and economic value,representing a developing new field in materials science technology.Biomedical materials contribute significantly to exploring the mysteries of human life and ensuring human health and longevity.

In the past decade,the market growth rate for biomedical materials and products has remained around 20%-25%.It is expected that within the next 10 to 15 years,the medical device industry,including biomedical materials,will reach the scale of the pharmaceutical market,becoming a pillar industry of the world economy in the 21st century.

Among biomedical metallic materials,titanium and its alloys have become the preferred materials for medical implants such as artificial joints(hip,knee,shoulder,ankle,elbow,wrist,finger joints,etc.),bone trauma products(intramedullary nails,plates,screws,etc.),spinal orthopedic internal fixation systems,dental implants,dental prostheses,orthodontic wires,artificial heart valves,and interventional cardiovascular stents,due to their excellent comprehensive performance.Currently,there is no better metal material than titanium alloy for clinical use.Developed countries and world-renowned suppliers of implantable products place great importance on the research and development of titanium alloys,launching a series of new medical titanium alloy materials,including bioactive titanium alloy biomimetic materials.They have also made many patented designs and developments in the surface treatment of medical titanium alloy materials,endowing them with better bioactivity to meet the physiological needs of the human body,thereby achieving the goal of enabling patients to recover as soon as possible.

The world population is nearly 6.5 billion.According to incomplete statistics,there are nearly 400 million disabled individuals,60 million with limb disabilities,and 2 billion dental patients.Currently,there are only 35 million implant recipients of biomaterials,with approximately 1.5 million joint replacements performed each year,which is far from the actual number of individuals needing replacements.Therefore,the market demand for biomedical materials has enormous potential.As the preferred choice for biomedical metallic materials,the demand for titanium and its alloys will also increase significantly,making it imperative to strengthen the research and development of medical titanium alloy materials.

2.Development History,New Progress,and Market Status of Biomedical Titanium and Its Alloys

The development and application of biomedical titanium and its alloys have gone through four landmark stages.

2.1 Early Application

In the early 1950s,commercially pure titanium was first used in the UK and the US to manufacture bone plates,screws,intramedullary nails,and hip joints.Since bone plates need to be shaped during surgery to fit the anatomical shape of the broken bone,commercially pure titanium(IS05832-2),which has undergone special processing,is still used to manufacture bone plates and matching screws,such as the full range of AO plates and screws produced by the Swiss manufacturer Mathys Medical Ltd.,which cannot be replaced by high-strength titanium alloys.Clinical findings have shown that using commercially pure titanium to manufacture intramedullary nails and hip joints has significant issues with insufficient strength and stiffness.To avoid the fracture failure of internal fixation implants and improve their strength,high-strength Ti-6A1-4V(IS05832-2)alloy has been adopted to replace pure titanium materials in countries like the UK,the US,Russia,and Japan.

2.2 Development Stage

The Ti-6A1-4V alloy itself has also developed,leading to the emergence of high damage tolerance titanium alloys with high fracture toughness,low crack propagation rates,and low interstitial elements,known as Ti-6A1-4VELI.Currently,over 80%of titanium alloy implant products still use this alloy.

Although the Ti-6A1-4V alloy has excellent performance,the presence of V elements can cause malignant tissue reactions and may have toxic side effects on the human body,prompting materials scientists to research new titanium alloy materials that do not contain V.Since the 1980s,biomaterials scientists in Germany and Switzerland have successively developed Ti-5A1-2.5Fe and Ti-6A1-7Nb alloys.Among these two alloys,the clinical application of Ti-6A1-7Nb(IS05832?11)alloy has been more successful.In 1985,Sulzer Medical Technology Company first used forged Ti-6A1-7Nb-Protasu1100 material to manufacture hip joint stems,obtaining production registration for clinical use,and the market response has been positive.Currently,such products have been introduced to China.The Swiss Mathys Company also uses Ti-6A1-7Nb alloy to manufacture non-expanding locking intramedullary nail systems(including tibia,humerus,femur)and hollow screws for treating femoral neck fractures.

2.3 Improvement Stage

In the 1990s,there were continuous reports regarding the potential hazards of AⅡto the human body in titanium alloy implant materials,suggesting that A1 could cause osteoporosis and mental disorders.Therefore,biomaterials scientists began to explore and research new types of titanium alloys that do not contain V or A1.Among the alloys successfully developed and clinically approved for use are Ti-13Nb-13Zr alloy(ASTM F1713-1996)and Ti-12Mo-6Zr-2Fe alloy(ASTM F1813-1997).

The Ti-13Nb-13Zr alloy,developed by American scientists in the early 1990s,is a bio-titanium alloy with low elastic modulus,high strength,high toughness,high fatigue strength,and good biocompatibility.Compared to Ti-6A1-4V,its elastic modulus is 30%lower,and its plane fracture toughness is 20%higher(65 MPa.m1/2);its bending and shear modulus is 30%-40%lower,and its corrosion rate in the same human-simulated body fluid is 40%lower.After cold and hot processing,while maintaining high strength,the modulus can drop to 50 MPa,making it closer to human cortical bone.Currently,this material is used by internationally renowned dental material manufacturers to produce dental implants.

The Ti-12Mo-6Zr-2Fe alloy is also a biomedically used titanium alloy that has been praised by internationally renowned metal manufacturers in recent years.This alloy has a lower elastic modulus,high strength,higher fracture toughness(90MPa.m1/2),good wear resistance,and excellent corrosion resistance,making it a well-performing sub-stable p-type biomedical titanium alloy.Compared to Ti-6A1-4V,its elastic modulus is 25%lower,providing better material flexibility,and its fracture toughness is about 80%higher(90:52),along with excellent mechanical properties:tensile strength is 20%higher than Ti-6A1-4V,and fatigue strength is 47%higher.One of the largest orthopedic specialty groups in the world,Stryker Corporation,through its subsidiary Stryker Howmedica OSTEONICS,uses the Ti-12Mo-6Zr-2Fe alloy(TMZFR BETA)to manufacture the MeridianTMZF femoral stem in the Howmedica Partnership system(hip prosthesis system),which has reached high standards required for orthopedic clinical quality,function,and clinical effect.Stryker SPINE also uses the TiMoZrFe alloy to manufacture the anterior cervical plate system(REFLEX Anterior Cervical Hate).These two products have been introduced to the Chinese market.

2.4 Innovation Stage

Without innovation,there is no progress.In recent years,there have been many innovative achievements in medical titanium alloys.

(1)Development and Application of Ni-Ti Shape Memory Alloy(NTSMA)

In the early 1980s,Ni-Ti shape memory alloy successfully entered orthopedic clinical practice,attracting the attention of orthopedic experts and clinicians,and was referred to as'magical metal'.This functional material has a unique shape memory effect,superelasticity,fatigue resistance,wear resistance,corrosion resistance,and good biocompatibility.It is composed of 56%(mass percentage)Ni and 44%(mass percentage)titanium.The deformation temperature of NTSMA used in orthopedic clinics is 0℃-5℃,and the recovery temperature is around 37℃.After fixing a fracture with NTSMA material,the temperature rises under body temperature or hot saline wet compress,causing shape recovery,but the bone restricts the material's recovery,thus generating a dynamic,continuous compressive or clamping force at the fracture ends to achieve fracture fixation.The basic research on NTSMA materials in China started later than abroad,but it is at an international level in clinical application research.In 2000,in the field of orthopedic implants,Lanzhou Ximai Memory Alloy Co.,Ltd.obtained product registration from the National Medical Products Administration,promoting the clinical application of NTSMA orthopedic implants.Currently,there are three companies in China registered to produce NTSMA bone fixation devices,mainly including staples,patellar devices,encircling plates,Ni-Ti bow-shaped memory compression bone fixators,and intramedullary nails.

NTSMA is also used in interventional therapy.Interventional therapy is an advanced non-surgical clinical technique that has developed rapidly in the past decade.This technique usually involves using puncture catheter technology under X-ray imaging to deliver specially designed wires,catheters,balloons,or stents to the site of lesions in the body for on-site treatment,characterized by minimal trauma,less pain,low risk,time-saving,reliability,and quick recovery.Interventional therapy materials include stent materials and delivery system materials,with stent materials primarily using NTSMA.In recent years,interventional therapy has developed rapidly in China,with an annual growth rate of 20%-30%.By 2002,nearly 150,000 patients had received interventional treatment.Currently,the materials required for interventional treatment mainly rely on imports,with over 20 companies having obtained FDA certification to enter the Chinese market.Their product quality and performance are superior to domestic products,with adequate after-sales service,but prices are high,ranging from 12,000 to 16,000 yuan per piece.Major suppliers include Johnson&Johnson Company Cordis Co.,Medtronic,Inc.,and Numed Canada Inc.;there are also some companies in China producing,such as Beijing Sitai New Technology Development Co.,Beijing Xinquan Co.,and Beijing Longzhou Feidu Memory Alloy Application Research Institute.

In addition,NTSMA is also used in dental orthodontic treatment.The NTSMA archwire produced by the Rare Metals Research Institute of Beijing(now Beijing Yuyin Yijin Co.,Ltd.)is not only sold and applied domestically but also exported overseas.

(2)Manufacturing of Bioactive Materials for Porous Ni-Ti(PNT)Alloy Interbody Fusion Cages

The Canadian company BIORTHEX has developed a cervical and lumbar interbody fusion cage made from patented porous Ni-Ti alloy material ACTIPORETM for the treatment of orthopedic spinal injuries.This material has about 65%porosity,with an average micropore size of 215μm-230μm,exhibiting bioactivity that promotes new bone growth through micropores and scaffolds,with interconnected multidirectional micropores creating capillary penetration,facilitating the entry of blood,essential nutrients,and bone marrow into the interbody fusion cage.The elastic modulus of this metal implant material is close to that of cancellous bone,thus avoiding the stress shielding effect,promoting bone reconstruction,and providing a good environmental support for the growth of bone cells.The interconnected micropores accelerate bone integration as bone growth cells and nutrients penetrate.A significant feature of this interbody fusion cage is that it does not require bone grafting(other materials for interbody fusion cages require bone transplantation using the patient's own iliac bone).After 3.1 years of implantation,bone reconstruction is completed inside the cage and matches the surrounding bone density.Animal tests have shown that PNT alloy has good biocompatibility.In 2000,this product obtained CE certification and began sales in Europe and parts of Asia.Currently,stricter clinical validation is underway to apply for FDA certification in the United States.This product is also expected to be introduced to the Chinese market soon.

(3)Manufacturing of Artificial Hip Joint Prostheses from Porous Titanium Alloys

Biologically fixed(non-bone cement)artificial joints are currently favored by orthopedic experts and clinicians.They require the material or surface of the hip joint stem to have bioactivity,which can induce bone cell growth,allowing for bone integration at the interface between the stem and the femoral medullary cavity,thus avoiding the drawbacks of using bone cement fixation,such as loosening,sinking,and dislocation after long-term use.Therefore,using porous titanium alloy materials at certain stages of the stem will endow the prosthesis with bioactivity,aiding in the physiological bonding of the stem to the medullary cavity.In the late 1990s,scientists from Germany and Japan successfully used directional solidification technology,utilizing hydrogen,oxygen,and nitrogen gases as foaming agents to produce directional solidified porous metal materials(i.e.,foam metal).The German company Krupp Medical Technology GmbH used this technology to produce porous titanium alloy femoral stem prostheses.

(4)Porous Titanium Alloy Coating Technology for Artificial Joint Prosthesis Manufacturing

Another method for manufacturing bio-fixed artificial joints is to create a porous surface on the titanium alloy joint stem.Tiny titanium beads(microsphere powder)can be sintered or applied using plasma spraying methods,with particles sintered(generally in double or triple layers)or plasma sprayed onto part of the surface of the joint stem,making its surface porous.This reduces the difference in elastic modulus between the implant and bone,which is beneficial for the growth of bone cells and the delivery of nutrients,thus achieving physiological bone integration.For example,the proximal end of the Exactech AcuMatchtm-A series hip joint stem in the United States uses titanium beads with a diameter of 0.28mm,arranged in a three-dimensional pattern.After sintering,the combined size of three rows of beads is 0.84mm,with an average pore size of 152μm and an average porosity of 35%,indicating that there is 35%space for bone ingrowth on the surface of the sintered titanium beads at the stem.

Most bio-fixed joint prostheses(hip and knee joints)use porous spraying(titanium microsphere powder)on their surfaces,such as those from Zimmer,Exactech,and Taiwan United Company.In addition to using titanium alloy beads(microspheres)for plasma spraying,in recent years,Encore Medical Corporation in the United States has invented the 3DMatrixTM porous spraying technology.This technology does not use spherical particles but rather a random three-dimensional irregular particle,with particle sizes ranging from 180μm to 850μm.After spraying,the surface pore size ranges from 250μm to 450μm,with a porosity of up to 61%.Clinical studies have shown that pore sizes of 100μm to 500μm are suitable for bone growth.This advanced porous spraying technology provides better bioactivity on the prosthesis stem surface,offering a better interface for bone growth.

(5)Hydroxyapatite(HA)coating technology for titanium alloy artificial joint manufacturing.

Using plasma spraying technology,a portion of the joint prosthesis stem is coated with hydroxyapatite(HA),which is also one of the methods for manufacturing bio-type artificial joints.Structurally,human bone itself is a natural composite material made of osteofibers and hydroxyapatite.Hydroxyapatite(Ca5(OH)(PO4)3)contains hydroxyl groups that can bond with human tissues,and its chemical composition and crystal structure are very similar to the hydroxyapatite that makes up human tissues.After implantation into human hard tissues,it bonds well with bone and can induce bone tissue to grow into the micropores,with minimal tissue response.After several months of implantation,a bony union can generally be achieved at the closely fitting interface,making it the preferred coating material among bioactive ceramics.

The bonding strength between the HA coating and the titanium alloy substrate is key to the clinical effectiveness of titanium alloy implants.As long as there is a macroscopic interface between the coating and the substrate,the bonding strength between the two cannot be satisfactory.Generally,the bonding strength between the coating and the titanium alloy substrate should not be less than 40MPa,with a coating thickness of 150μm to 200μm.If the coating is too thick,the bonding strength decreases,and the coating is prone to cracking.Therefore,the entire plasma spraying process is operated by robots to ensure uniformity in coating thickness.The coating contains micropores and larger pores,exhibiting porosity and randomness,with micropore sizes ranging from 3μm to 5μm and larger pore sizes ranging from 50μm to 100μm.The size of the pores can be detected under a scanning electron microscope,and at the same time,HA must maintain continuous purity(generally above 99.9%)and a stable crystalline structure.

Most joint product manufacturers at home and abroad have adopted this technology to manufacture bio-type titanium alloy artificial prosthesis stems.

(6)Al2O3 ceramic coating technology for titanium alloy artificial joint manufacturing.

Using plasma spraying technology,α-Al2O3 micropowder with a purity of 99.8%is sprayed onto the hip joint prosthesis stem(stem material Ti6A14V),and then cooled in liquid CO2,formingγ-Al2O3 at the interface.It is also required that the crystallization strength between the substrate and Al2O3 should not be less than 20MPa,which is also one of the methods for manufacturing bio-type(non-bone cement)artificial joints.Al2O3 ceramic materials are also used to manufacture the femoral head and the inner lining of the hip joint socket.Observations from autopsies of deceased patients who used prostheses made from the above materials and other clinical tests indicate that Al2O3 ceramic material debris does not cause inflammatory reactions in the synovial tissue within the joint capsule,nor have there been any signs of synovial hyperplasia or necrosis.This type of prosthesis is suitable for younger patients and those with higher activity levels post-surgery.Thus,it is evident that Al2O3 ceramic material has excellent biocompatibility with human tissues.Al2O3 ceramic material also has high physical stability,does not undergo biological degradation,has excellent hydrophilicity on its surface,can effectively form a water molecule film to reduce friction,and has high hardness and fatigue strength,with wear resistance 30 to 40 times higher than CoCrMo alloy.Joint products from Italy's LIMA orthopedic equipment company and France's SERF medical technology company use this manufacturing method and process.Joint products from the Beijing Aeronautical Materials Research Institute's Bermuda Materials Company also use this process.

(7)Hydroxyapatite(HA)-glass-titanium composite materials for artificial joint manufacturing.

In the late 1990s,Japanese materials scientist Shigeo Maruno and others developed a new type of bio-medical titanium alloy composite material for artificial joint manufacturing.This material uses Ti-6A1-4V alloy as the substrate,selecting glass powder(aluminosilicate glass,i.e.,Al2O3-B2O5-SiO2,approximately 85%by volume,with the remainder being glass-modifying oxides Na2O,K2O,Li2O,ZrO2,and TiO2,with an average diameter of 17μm)that has good bonding properties with the substrate material,stable biochemical properties,safety,and excellent bonding performance with HA powder,and mixes high-purity HA powder to coat the titanium alloy substrate surface to form HA-containing glass-titanium composite materials through sintering.Another key aspect of this material research is that the thermal expansion coefficient of the sintered composite layer must be lower than that of the titanium alloy substrate.Only in this way can the contact interface between the composite layer and the titanium alloy substrate generate a dense,stable,and tightly bonded composite layer due to thermal diffusion reactions.

Artificial hip joint prosthesis stems made from HA-G-Ti composite materials have been preliminarily clinically validated,proving to be a durable,well-fixed,and cost-effective artificial hip joint prosthesis.The thickness of the composite layer HA-G can be adjusted arbitrarily,has excellent biocompatibility,and the HA-G composite layer has good bonding with the substrate,with no peeling or delamination observed.Long-term clinical effects need further observation,so this material is also a bio-medical titanium alloy material with great market development potential.

(8)Anodic oxidation coloring treatment of titanium and its alloys for orthopedic instruments,plastic surgery,and dentistry.

The anodic oxidation coloring treatment of titanium and its alloy surfaces enhances their functionality by improving the wear resistance,corrosion resistance,and cyclic fatigue resistance of the titanium alloy matrix in the human body environment through the coating of an oxide film on the surface.Additionally,the oxide film on the surface largely addresses the issue of metal ion leaching,reducing cytotoxicity and significantly improving the biocompatibility of the implants.In terms of aesthetics,the increasing variety and specifications of titanium alloy implants have also brought challenges to clinical identification.The coloration of the surface oxide film,as a unique property of titanium alloys,can be used to identify different specifications and categories of implants during surgery,facilitating surgical operations.Furthermore,due to titanium's good biocompatibility and corrosion resistance,lightweight,and comfortable wear,its clinical applications as dental prosthetics(implants)and orthopedic repair bodies are gradually increasing.The restoration of dental prosthetics is no longer solely focused on the recovery of functions such as chewing,pronunciation,and lifespan;the aesthetic requirements for dental prosthetics are also increasing,and the color beauty of dental prosthetics can provide visual enjoyment.This advantage is even more pronounced in orthopedic repair.

The reason why the surface of titanium displays different colors after oxidation is that the main component of the oxide film formed on the surface of metallic titanium is titanium oxide.The film-like substance composed of this component is transparent and can strongly reflect and refract light.When titanium is heated in an oxygen-containing atmosphere or subjected to anodic oxidation treatment,a titanium oxide film several hundred angstroms thick is deposited on the surface.If light is incident on the titanium coated with the oxide film,the reflected light from the surface of the oxide film will interfere with the light reflected from the metal interface through the transparent oxide film,resulting in various beautiful interference colors.With different thicknesses of the oxide film,the titanium surface can exhibit various colors such as yellow,green,gold,and pink.

The main methods for the oxidation coloring of titanium include anodic oxidation,atmospheric oxidation,and chemical treatment.Additionally,there are methods such as plasma nitriding,nitrogen ion implantation,and physical-chemical vapor deposition.

Compared to the other two oxidation coloring methods for titanium,the anodic oxidation method has a simple process,a rich variety of surface coloring tones,and easy control of the tones,making this oxidation method a promising oxidation coloring technology.

Bone fixation implants and instruments usually use anodic oxidation for surface coloring treatment,with colors including golden yellow,bronze,sapphire blue,bright brown,rose red,and elegant green.

3.Preliminary analysis of the research and market application status of biomedical titanium and its alloys in China and existing problems.

3.1 Research and market application status of biomedical titanium and its alloys.

Since the mid-1980s,China has been at the international advanced level in clinical and application research on nickel-titanium shape memory alloys for medical implants.The Shanghai Steel Research Institute,Tianjin Metallurgical Materials Research Institute,and the Rare Metals Research Institute of the Beijing Nonferrous Metals Research Institute have collaborated with local medical experts and professors to develop many medical implant products,such as encircling steel plates,patellar claws,saddle nails,intramedullary nails,artificial joints,and dental arch wires.However,it was not until 2000 that the first nickel-titanium shape memory alloy product(from Lanzhou Ximai Memory Alloy Co.,Ltd.)obtained production registration from the National Medical Administration.

Although China has abundant titanium reserves,it is relatively lagging in medical titanium,unable to compare with European and American countries in terms of scientific research,equipment,technology,processes,or applications.In 1998,the Orthopedic Instrument Factory of Tianjin Medical Device Industry Company was the first to obtain trial production registration for"titanium bone plates"and"titanium bone screws"issued by the National Medical Administration,becoming the first domestic titanium implant production enterprise.This enterprise achieved good economic benefits that year.In the following years,titanium implants were produced by domestic medical device manufacturers like bamboo shoots after rain.Currently,well-performing domestic companies include Changzhou Wujin Medical Device Factory No.3 and Changzhou Kanghui Medical Device Co.,Ltd.However,many problems have also arisen during specific use,such as implant fatigue fracture,difficulty in shaping during surgery,and even many medical disputes,which are certainly closely related to material selection.

In 1992,China established the processing material standards for titanium and its alloys for surgical implants(GB/T 3810-1992),but the types of alloys were very few.In 1997,the above standard was revised to GB/T 13810-1997.However,in actual use,surgical implant manufacturers did not fully understand the performance of this material,and material manufacturers did not have internal control standards specifically for surgical implant materials,such as the Ti-6Al-4VELI high damage tolerance alloy standard commonly used by foreign surgical implant manufacturers,which has not yet been promoted and applied domestically.

In the research and development of biomedical titanium and its alloys,Professor Wang Guisheng from the Beijing Nonferrous Metals Research Institute,Professor Wei Shouyong from the Baoji Nonferrous Metals Processing Plant,and Professor Li Zuocheng from the Biomaterials Research Center of the Northwest Nonferrous Metals Research Institute have done a lot of beneficial work and exploration.

In the development of the Ti-6Al-7Nb alloy,starting in 1996,with the project initiated by the National Medical Administration,through the joint efforts of the Beijing Nonferrous Metals Research Institute,Baoji Nonferrous Metals Processing Plant,and their cooperative units,laboratory research and industrial trial production were successively completed.The chemical composition and mechanical properties of the material fully comply with the IS05832-11 regulations,and the metallographic structure is equivalent to A4 grade in the ETYC2(European Titanium Products Technical Committee)standard,meeting the requirements of ISO5832-11 for microstructure.In addition to small batch trial production,in 1999,Baoji Nonferrous Metals Processing Plant also exported more than ten tons of finished bars to the United States,earning hundreds of thousands of US dollars.This material passed expert appraisal in 2001,and this project also won the first prize of the 2001 China Nonferrous Metals Industry Science and Technology Award.

Currently,this material is prepared to be included in the revised version of the national standard for non-active surgical implants for bone fusion(GB/T 2417).The national standard for Ti-6Al-7Nb bars for surgical implants is also being drafted.

3.2 Existing problems.

Currently,although many implant production factories have made titanium alloy materials for implants a key focus of product development,the quantity of medical titanium is rapidly increasing(relative to itself),but there are still many misconceptions in China's medical titanium sector:implant manufacturers lack unified,high-quality internal control material standards,lack scientific understanding of material grades and performance,and blindly believe that anything made of titanium is good,leading to multiple cases of implant fractures and failures in the body due to material issues,resulting in medical disputes.

Due to the volume of use,material manufacturers consider cost factors,emphasizing economic benefits while neglecting social benefits.Domestic material manufacturers have not yet produced titanium products specifically for medical use,such as the Ti-6Al-4VELI alloy commonly used by European and American companies,including profiles like arc-shaped cross-section strips,small diameter hollow thick-walled pipes,and thick plates for joint forging.

Due to various reasons,our country has not put enough effort into the research and development of titanium alloy materials for medical use.The processing and surface treatment technology levels of titanium alloy implants are significantly behind those of advanced countries in the world.

Although the State Council has established a national titanium industry management office,due to the specificity of medical materials,our country has not established a dedicated branch or industry association responsible for or coordinating the research and development,material standards,material quality control,product processing technology consultation,and communication regarding medical titanium,resulting in a lack of unified industry management.

4.Outlook

(1)Attention should be paid to the research and development of biomedical titanium alloy materials with low elastic modulus,high wear resistance,corrosion resistance,high fracture toughness,low crack propagation rate,high damage tolerance,and excellent biocompatibility.

(2)The compatible elements in the alloy should prioritize the addition of non-toxic elements,such as mainly adding non-toxic'biological'metal elements like Nb,Zr,Ta,Sn,Pt,etc.

(3)Efforts should be made to improve the quality level of biomedical titanium and its alloy processing materials in our country.Manufacturers should focus on and meet the market demand for medical titanium,and the material quality control standards should align with international standards,while also strengthening the standardization of materials.

(4)There should be an increase in the development and research efforts of materials,taking the path of joint development among material research institutes or higher education institutions,material production factories,medical research institutions,and clinical medical experts,integrating material development,biocompatibility testing,and clinical medical verification to accelerate the development of new biomedical titanium alloy materials with broad application prospects.

Author:He Baoming