Titanium and titanium alloy metal powder injection molding technology

Titanium and titanium alloy metal powder injection molding technology

 

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Summary

Titanium and titanium alloys have both low specific gravity, high specific strength, excellent biocompatibility, and good corrosion resistance, and have great application potential in fields such as aerospace, biomedical, chemical, and automotive.

Titanium and titanium alloy metal powder injection molding (MIM) technology can achieve large-scale and low-cost preparation of small and medium-sized complex shaped titanium products, which is of great significance for promoting the production and application of titanium and titanium alloy products.

This article introduces the characteristics and advantages of metal powder injection molding of titanium and titanium alloys. It summarizes the research progress of titanium and titanium alloy metal powder injection molding technology from the aspects of powder raw materials, binder systems, powder injection molding, debonding, and sintering. In response to the main problems currently existing, it analyzes the research direction and development prospects of metal powder injection molding of titanium and titanium alloys.

Keywords titanium; Titanium alloy; Injection molding; Research progress classification number TF125.2; TF125.2+2

(Editor's note: English introduction omitted...)

Since the industrial production method of obtaining metallic titanium from ore was mastered in the 1840s, titanium and titanium alloys have been widely used in industrial and commercial facilities. However, compared with steel, its annual output is still small, and because of the high cost of raw materials, its application scope is mostly limited to the marine industry, chemical industry, aerospace industry, medical devices, implants, luxury goods and other industries with high requirements for material performance.

At present, in addition to the high prices of raw materials, the difficulty of processing and forming titanium and titanium alloys greatly limits their application scope.

The machinability of titanium and titanium alloys is poor, and traditional machining methods have expensive equipment and low processing efficiency, greatly increasing their processing costs; The structure of titanium parts that can be machined is very simple, and due to the limitations of processing methods, most of them cannot achieve design solutions that can maximize material performance.

In this context, metal injection molding (MIM), which has the advantages of high raw material utilization and low batch production cost, has become an ideal titanium and titanium alloy processing process [1-4].

The metal powder injection molding process usually includes several basic processes such as injection material preparation, injection molding, debonding, sintering, and necessary post-processing.

As shown in Figure 1, the metal powder and organic binder components are first mixed, mixed, and granulated to prepare an injection material. Then, the injection material is injected into the mold at a certain temperature and pressure, cooled, and demolded to obtain a green product with a specific shape. Then, through the debonding process, all organic components except for metal powder are removed from the green product, forming a debonding green product. Finally, sintering is carried out to obtain the desired performance of the product.

The metal powder injection molding technology has achieved an organic combination of injection molding and traditional powder metallurgy technology, overcoming the disadvantages of high machining cost, simple shape of traditional molding process, low production efficiency of isostatic pressing and injection molding process, many defects in traditional casting process, and low tolerance accuracy. It has greatly promoted the production and application of titanium and titanium alloy products (as shown in Figure 2).

1 Flow chart of titanium and titanium alloys manufactured by MIM

 

2 Applications of titanium and titanium alloys manufactured by MIM

 

Research status of titanium and titanium alloy metal powder injection molding

Research has shown that the mechanical properties, corrosion resistance, and biomedical properties of titanium and titanium alloy injection molded products are greatly influenced by four aspects: relative density, impurity content, alloy elements, and microstructure.

After the injection molding product is sintered, its relative density is about 95%, and there will be a certain proportion of residual pores.

These residual pores will become the crack source when the sample breaks, and have a greater impact on the tensile strength, ductility, fracture toughness, fatigue strength and other mechanical properties of the material. Therefore, the higher the relative density of titanium and titanium alloy injection molded products, the better their mechanical properties.

Impurity elements such as oxygen, carbon, nitrogen, hydrogen, etc., especially oxygen, can increase the yield strength, tensile strength, and hardness of materials, reducing ductility. At the sintering temperature, impurity elements dissolve in the matrix titanium. Due to the lack of effective reducing agents, it is difficult to control the impurity elements in titanium and titanium alloys during the sintering process. This requires minimizing the amount of oxygen added to the raw materials and each subsequent process step.

The microstructure of titanium and titanium alloys, including the grain size and phase composition after sintering, can affect the mechanical properties of the material. Overall, injection molded titanium and titanium alloy materials with excellent performance have high density, low impurity content (usually oxygen content), appropriate alloy composition, fine grain size during densification, and fewer defects [5].

1.1 Powder raw materials

The selection of powder raw materials is an important step in the titanium powder injection molding process. The particle size distribution and morphology of the powder directly affect the fluidity and formability of the injection molding compound, the shape retention of the green body during the debonding process and the shrinkage rate during the sintering process.

The commonly used methods for preparing titanium and titanium alloy powders include mechanical method and atomization method.

The shape of the powder obtained by mechanical methods such as ball milling, stirring ball milling, high-energy vibration ball milling, and airflow pulverization is generally irregular or angular.

The hydrogenation dehydrogenation (HDH) process utilizes the obvious embrittlement characteristics of titanium after hydrogen absorption. It is crushed by mechanical grinding or airflow crushing, and then subjected to dehydrogenation to obtain irregularly shaped titanium powder, as shown in Figure 3 (a). The atomization method (such as inert gas atomization, plasma beam rotating electrode atomization and electrode induction melting gas atomization) can be carried out in a completely inert atmosphere, so as to maintain the high purity of raw powder. The prepared powder is spherical in shape and has a fairly wide particle size distribution, with good stacking performance, as shown in Figure 3 (b).

In addition, unlike the production technology of steel powder, the production of finer titanium powder is more difficult. As the particle size decreases, the specific surface area increases, and the content of impurity elements also increases.

Typically, MIM uses titanium powder with a particle size of less than 45 μ m. When the powder particles are too large, the injection process is prone to powder binder separation and the formation of defects. It is necessary to fully consider the design of injection material composition and mold design [5].

Fig.3 HDH (a) and gas atomized (b) titanium powder used in MIM

1.2 Adhesive

The binder is a carrier that exists in stages throughout the entire injection molding process, and its main function is to evenly fill the mold with powder in a fluid state, forming the desired shape, and maintaining it until the pre sintering stage.

In the injection molding process, the binder should have the following characteristics: low melting point, good wettability to powder particles, and rapid solidification, which is convenient for the preparation of injection materials; Has good fluidity at injection temperature; After forming, it can be easily removed from the billet, with less residual material and non-toxic and non corrosive decomposition products.

Generally speaking, the binder components include at least the main component and secondary components:

The main component is used to wet metal powder particles and provide necessary flowability, while the secondary component ensures that the injection green body still has sufficient strength during the injection process and after the removal of the main component of the binder.

In most cases, the binder system has a third component, such as surfactants, to improve the compatibility between metal powders and polymers.

According to the different main components in the binder components, the commonly used binder systems can be divided into wax based systems, aromatic compound based systems, polyoxymethylene systems, and water-based systems.

1.2.1 Wax based binder

The commonly used waxes for wax based system binders include several short chain polymers such as paraffin, beeswax, palm wax, etc. They have low melting point, good wettability, short molecular chains, low viscosity, and smaller volume changes during decomposition compared to other polymers, which is conducive to ensuring product dimensional accuracy.

The commonly used secondary components of wax based systems include polypropylene, polyethylene, ethylene vinyl acetate copolymer, and high molecular weight polymethyl methacrylate. In addition to wax and skeleton binders, a surfactant such as stearic acid is usually added to improve the compatibility between powder and polymer.

The earliest reported wax based binder system in literature was Kaneko et al. [6], which used paraffin polybutyl methacrylate ethylene vinyl acetate copolymer dibutyl phthalate as a binder and titanium powder to prepare a remark injection material. The powder loading was 56%, and after debonding, it was sintered at 1300 ° C and 1.3 Pa. The obtained sintered sample had a relative density of 94% and a compressive strength of 1000 MPa, but due to the high impurity content, it had almost no ductility.

Kato et al. [7] studied a two-step debonding process combining vacuum debonding and argon atmosphere debonding, which significantly reduced the carbon and oxygen content in sintered parts.

Guo et al. [8-9] used polyethylene glycol with better wettability to replace some paraffin and developed a paraffin polyethylene polyethylene polypropylene stearic acid binder system, which was used in injection molding of pure titanium and titanium aluminum vanadium alloys. The sintered parts had good shape retention and small inch wave motion. Due to the reduction of oxygen and carbon content, the performance was greatly improved, resulting in good performance.

In addition, researchers have used palm wax as a partial substitute for paraffin wax [10-13] and palm oil as a complete substitute for paraffin wax [14] for a wax based binder system, which has good forming effects. However, due to the oxygen element contained in palm wax itself, it is also a source of oxygen enhancement,

At present, the optimal wax based binder system reported in the literature was proposed by Friederici et al. [15]. During the experimental process, four binder ratios were formed by adjusting the proportions of paraffin, low-density polyethylene, and stearic acid, and different injection materials were formed, debonded, and sintered based on these ratios. A sample with a relative density of 98.1% and a chemical composition that meets the requirements of secondary pure titanium was obtained.

Wax based binder systems play an important role in injection molding, but due to the low efficiency of solvent debonding using organic solvents, researchers have continuously innovated and developed new binder systems.

1.2.2 Aromatic compound based binders

Aromatic compounds (such as naphthalene, anthracene, etc.) can dissolve at very low temperatures, and under low pressure conditions, they can be directly transformed from solid to gas through sublimation at temperatures below their melting point. Using aromatic compounds as binder components can greatly improve the efficiency of the debonding process.

Weil et al. [16-18] used aromatic compounds in titanium metal powder injection molding. In its research, dense titanium aluminum vanadium alloys and porous titanium aluminum vanadium alloys were prepared using naphthalene, 1% mass fraction of stearic acid, and 3% to 12% mass fraction of ethylene acetate ethylene copolymer as binders.

During the experiment, due to the direct sublimation of naphthalene into gas, no liquid phase appeared during the debonding process, and the sample volume did not change. Unlike solvent degreasing, the surface energy involved in the sublimation method is relatively low, which means that common degreasing defects such as deformation and cracking can be avoided. In the end, the relative density of the sintered sample was 96.6%, and the carbon content did not increase.

Although the adhesive system has achieved excellent product performance, the aromatic compounds in the system still have an impact on the environment and physical health, and have not been further studied or applied on a large scale.

1.2.3 Polyoxymethylene based binder

Polyformaldehyde was first used in the binder system by Celanese Corp in 1984, and later developed by BASF, making it possible for the binder components to contain no wax or small molecular weight components [19].

Polyformaldehyde is the main component of this binder system, and polyethylene (PE) is gradually added as a skeleton binder during the later development process.

At present, BASF has formed injection molding materials based on this binder system, covering many materials such as low alloy steel, stainless steel, tool steel, titanium and titanium alloys, and ceramics.

The significant characteristic of polyformaldehyde is its sensitivity to acidic reagents and its susceptibility to acidic decomposition. Therefore, the green body can be treated in an acidic atmosphere below its softening temperature. The process of polyoxymethylene is in a solid state, avoiding defects such as cracks and expansion caused by boiling of binder components. Moreover, the deformation is small, the shape retention is good, and the size control is accurate.

In addition, due to the high diffusion rate, compared to other degreasing methods, the degreasing rate is higher, reaching 10 times the rate of traditional solvent debonding, while allowing for thicker size debonding [20].

Although the polyoxymethylene based binder system has many advantages mentioned above, it also has many disadvantages.

The catalytic debonding process often uses highly corrosive nitric acid vapor as a catalyst. On the one hand, polyformaldehyde may decompose during the preparation of injection materials and injection molding stages, producing highly toxic formaldehyde. Moreover, the decomposition products need to be removed through two-step combustion. On the other hand, the acidic atmosphere that plays a catalytic role has a greater corrosiveness to the equipment, requiring more investment.

1.2.4 Water based binder

The debonding solvents (such as heptane and hexane) or the decomposition products of bonding agent components (aromatic compound monomers and formaldehyde) used in the aforementioned several bonding agent systems are more or less harmful to the environment and operators. Therefore, the development and utilization of environmentally friendly solvent bonding agent systems is of great significance.

The existing environmentally friendly binder system uses water as the debonding solvent.

According to the different roles of water in the preparation of injection materials, this kind of binder system can be divided into gel based and non gel based.

The common polymer used in non gel based systems is polyethylene glycol, which has good performance and is cheap and easy to obtain. Low molecular weight polyethylene glycol can be quickly and almost completely removed at 60 ° C, with a commonly used molecular weight range of around 500-2000. The commonly used skeleton binder is polymethyl methacrylate with a molecular weight of 10000.

Sidambe et al. [21] used a water-soluble binder component of polyethylene glycol polymethyl methacrylate stearic acid to study at a powder loading rate of 69%.

In the experiment, polyethylene glycol was completely removed in water at 55 ° C after 5 hours, and polymethyl methacrylate was completely removed in a hot debonding argon gas flow at 440 ° C. The final oxygen content (mass fraction) of the prepared sample is 0.2%, with corresponding tensile strength of 850-880 MPa and elongation of 8.5% -16%, meeting the ASTM grade 5 Ti standard.

Most gel based binders are natural substances, such as cellulose, starch agar, etc.

Tokura et al. [22] used agar to replace polymer binders in titanium powder injection molding and studied the thermal stability, solubility, and injection material viscosity of this binder system.

Suzuki [24] et al. prepared 97.3% samples with relative density using agar (molecular weight 82 500) binder containing 4% mass fraction. The carbon and oxygen mass fractions of the samples are 0.33% and 0.3%, respectively. The yield strength is 539 MPa, and the elongation is about 10%. The experimental results show that when using high molecular weight agar, the gel strength increases, but the residual carbon and oxygen content is high, resulting in lower sintering density, tensile strength and elongation of the sintered pieces.

The non gel based water-based binder is easy to control, the degreasing equipment is cheaper than other degreasing methods, and the binder is biodegradable and non-toxic to microorganisms, but the treatment of wastewater for degreasing requires additional costs.

It is difficult to control the size of the final parts produced by gel based binder system injection molding compound, and the composition is not stable enough, so the process conditions and quality control are difficult, and further research and optimization are still needed.

1.3 Injection molding, debonding, and sintering

The injection molding process parameters are determined by the performance of the injection material and the geometric shape of the target product.

As mentioned earlier, the particle size of titanium powder is usually coarse, which is prone to powder binder separation compared to stainless steel material injection molding. Before injection molding, appropriate forming process parameters should be developed based on the rheological properties of the injection material to reduce defects in the formed billet.

Wang et al. [25] prepared injection molding materials using Ti-6Al-4V alloy combined with a powder wax based binder system, and tested and analyzed the rheological properties of the injection materials under different powder loading amounts and temperatures, providing a basis for developing appropriate forming parameters for the injection molding process.

Park et al. prepared injection materials using aerosolized titanium powder, HDH titanium powder, and spheroidized HDH titanium powder, and measured their rheological properties and debonding behavior. They proposed a formability index for the injection material and evaluated its performance based on this. The analysis results provided a theoretical basis for the simultaneous use of HDH powder and aerosolized powder in the injection material system.

Barriere et al. [27] explored the optimal process parameters for producing metal injection molded parts without defects and with the required mechanical properties based on experimental and numerical simulation processes. Based on modeling techniques, a two-phase flow equation and a newly developed explicit algorithm were used to predict material separation phenomena during the injection process using numerical simulation.

Chen et al. [28] used a hydrogenated dehydrogenated Ti-6Al-4V pre alloy powder and water-soluble binder system to prepare a remark injection material, and then measured the removal rate of water-soluble binder component polyethylene glycol in samples of different thicknesses at different temperatures. A diffusion controlled debonding mathematical model was established to determine the debonding mechanism of the binder system.

Sidambe [29] and others used the Taguchi methods to determine the optimal combination of sintering temperature, time, heating rate, atmosphere and other parameters.

Nor et al. [30] prepared Ti – 6Al – 4V injection material by using palm stearate and polyethylene binder system, and formulated the optimal production process by using Taguchi methods. Finally, a sample with yield strength of 934.4 MPa and elongation of 10% was obtained, and its overall performance met the requirements of ASTM B348-02 medical titanium alloy.

Obasi et al. [31] prepared Ti-6Al-4V specimens with properties meeting the requirements of ASTM B348-02 titanium alloy grade 23, and studied the effects of changes in basic process parameter systems on the thermal degreasing and sintering processes of Ti-6Al-4V powder MIM components.

Limberg et al. [32] prepared Ti-45Al-5Nb-0.2B-0.2C using a mixture of elemental powders during the injection molding process, and studied the effects of sintering time and atmosphere on tensile properties and microstructure. A sample with a tensile strength of about 630 MPa was obtained.

Guo et al. [8-9] prepared pure titanium and Ti-6Al-4V materials using injection molding technology, and studied the effects of heat treatment processes such as hot isostatic pressing and annealing on the properties of the alloy material. The heat treatment effect was qualitatively and quantitatively characterized through microstructure and mechanical properties testing, and its microstructure is shown in Figure 4.

A remark injection material is prepared by mixing atomized titanium powder, hydrogenated dehydrogenated titanium powder, and wax based binder system. After injection molding, solvent debonding is carried out in a mixture of heptane and ethanol. The binder is completely removed after heating to 350, 420, and 600 ° C at a certain heating rate, and the sintering temperature is 1230 ° C for 3 hours. Finally, the tensile properties of the sintered sample were 389-419 MPa, and the elongation was 2-4%.

The members of our research group [33] prepared pure titanium samples using a system of aerosolized titanium powder and water-soluble binder, and studied the effects of sintering temperature and holding time on the properties of pure titanium samples. The sintering process was carried out under a vacuum degree of 10-4-10-3 Pa, with a sintering temperature of 1350 ° C and an elongation of 20.3% obtained after holding for 3 hours. The samples fully comply with the best powder metallurgy performance of ASTM F2989-13, with a relative density of 96.9% and a tensile strength of 443 MPa, Biomedical Grade II Pure Titanium Standard.

4 Microstrctures of Ti (a) and Ti-6Al-4V (b) samples prepared by wax-based feedstocks

2 New Titanium and Titanium Alloy Injection Molding Materials

Titanium and titanium alloys are currently widely used in orthopedics, dental equipment, and medical implants. However, due to the difference in mechanical properties between titanium and human bone (with an elastic modulus of about 20 GPa), stress shielding effects are generated at the bone/implant interface, which may greatly compromise long-term clinical outcomes, as shown in Figure 5.

Therefore, researchers have adjusted the mechanical properties of titanium materials by changing their structure and alloy composition, making them closer to the structure and performance of natural bones in the human body.

5 Comparison of elasticity modulus of biomedical titanium alloys

2.1 Porous titanium materials and titanium ceramic composites

Porous titanium materials and new titanium alloy system materials have appropriate pore structure and mechanical properties, making them ideal materials for orthopedic replacement implants.

On the one hand, it can effectively reduce the stress mismatch between the implant and bone tissue, thereby reducing the stress shielding effect and achieving the long-lasting and effective function of the implant; On the other hand, porous structure is a necessary condition for bone cells to grow into the implant body, and the interconnected porous structure can allow a large amount of body fluid to pass through, further promoting the growth of bone cells.

Gu et al. formed a new type of TC4 alloy with an open pore structure by adding TiH2 as a foaming agent and activator to titanium aluminum vanadium element powder, with uniform pore size distribution and pore size ranging from 90 to 190 μ m. The porosity is about 43%~59%, and the elastic modulus ranges from 5.8 to 9.5 GPa. Engine et al. [35] prepared multi microporous titanium alloys using powder injection molding (PIM) technology combined with pore forming agent technology, and studied the effect of the amount of pore forming agent polymethyl methacrylate on the density, compressive strength, and elastic modulus of the alloy.

Tuncer et al. [36] used a system of atomized spherical powder, HDH titanium powder, and wax based binder to study the effect of initial powder on the performance of the final porous titanium product by adding a certain amount of NaCl and KCl as pore forming agents. Furthermore, by adjusting the amount of pore forming agents, a porous titanium material with the required porosity and pore size for medical implants was obtained, and the chemical composition of the material could meet the third grade pure titanium standard.

Chen et al. [37] used NaCl as a pore forming agent and hydrogenated dehydrogenated titanium powder wax based injection material to prepare injection molded samples. The obtained samples had a porosity of 42.4%~71.6% and a pore size of 300 μ m. As shown in Figure 6. By adjusting the amount of NaCl used, interconnected pores can be formed inside the injection part, and their mechanical properties are similar to those of cancellous bone.

Barbosa et al. [38] first used Fe22Cr powder to test the rheological properties of injection materials with different binder systems. Based on the performance test results, an appropriate wax based binder system was selected. Then, Ti powder and pore forming agent NaCl were combined for warm pressing and multi-component injection molding. After degreasing and sintering, a spine implant component with a dense core and external porosity gradient was prepared.

6 Porous titanium injection molding component using NaCl as space holder

Hydroxyapatite (HA), with the same chemical composition and crystal structure as human natural bone tissue, has unique advantages in bone replacement and bone reconstruction, and has begun to play an increasingly important role in biomedical devices.

However, due to its high brittleness and poor mechanical properties, HA cannot be used as a load-bearing component alone, resulting in the emergence of a new type of biomedical material composed of HA and titanium materials.

Thian et al. [39-42] studied the preparation of Ti6Al4V/HA composite materials using injection molding method. Firstly, Ti6Al4V/HA composite powder was prepared using the ceramic slurry method. Then, the prepared powder was mixed with commercial binder PAN-250S to prepare a remark injection material. The rheological properties of the injection material were tested, and the effects of heating rate and debonding atmosphere gas flow rate on debonding defects, binder removal amount, and residual carbon content during the debonding process were studied; The effect of sintering process parameters (heating rate, sintering temperature, holding time, cooling rate, etc.) on the performance of the final sample, resulting in a porosity of about 50% of the sample; In addition, the biological degradation process of the prepared Ti6Al4V/HA material in the body fluid environment was analyzed and characterized through the test results of mechanical properties.

2.2 New Titanium Alloy Materials

The biomedical field, as an important branch of titanium material application, its application demand direction directly affects the development trend of titanium materials.

Early titanium materials used pure titanium（ α Mainly composed of phases, but pure titanium materials have lower strength and poor wear resistance, leading to the development of high-strength and high toughness materials represented by Ti6Al4V, Ti6Al7Nb, and Ti5Al2.5Fe α+β Type A alloy.

Aust et al. [43] successfully manufactured bone screw materials with excellent performance using Ti6Al7Nb powder and a wax based binder system (paraffin+PE+stearic acid), as shown in Figure 7. The material has a relative density of 97.6%, tensile strength of 815 MPa, yield strength of 714 MPa, and elongation of 8.7%.

Research results have shown that alloy elements such as Al and V in widely used titanium aluminum vanadium alloys and titanium aluminum niobium alloys release cytotoxic Al and V ions after implants enter the human body, causing harm to the human body.

As a result, the researchers conducted a series of new generation experiments that contain biosafety elements such as Nb, Ta, Zr, Mo, Sn, but not Al and V elements β Development of titanium alloy systems.

Currently developed and researched β Biological titanium alloys mainly include Ti-15Nb, Ti-13Nb-13Zr, Ti-35Nb-7Zr-5Ta, Ti-12Mo-6Zr-2Fe, Ti-35.3Nb-5.1Ta-7.1Zr, and Ti-29Nb-13Ta-4.6Zr [44]. Due to various limitations such as powder manufacturing technology, these alloy systems are not widely used in powder injection molding processes.

Zhao et al. [45] used titanium powder and niobium powder for injection molding experiments to successfully prepare TiNb dual phase alloys with a relative density of about 95%. By testing the mechanical properties of green billets, debonding parts, and sintered parts, as well as observing and comparing the microstructure of sintered parts with different alloy composition contents, the effect of Nb content on the microstructure and mechanical properties of the alloy was studied.

Arokiasamy et al. [46] prepared a Ti-5Fe-5Zr alloy by adding Fe and Zr elements to HDH pure titanium powder, and measured the mechanical properties of the alloy. Based on the test results, the mechanism of residual pores and the effect of TiC on the properties of the alloy material was obtained.

 

Fig.7Ti6Al7Nb 骨钉Ti6Al7Nb bone screw prepared by MIM

3 Outlook

The low specific gravity, high specific strength, excellent biocompatibility, oxidation resistance, and good corrosion resistance of titanium and titanium alloys have great development potential in applications such as aerospace, medical, chemical, automotive, and daily consumer goods.

Compared to traditional processing techniques such as forging, casting, and machining, powder injection molding technology has obvious advantages, such as uniform alloy composition, high raw material utilization rate, and strong production capacity for large quantities of complex shaped parts, which can greatly promote the production and application of titanium and titanium alloy products.

Although some progress has been made in the research of titanium and titanium alloy injection molding, a series of problems still need to be solved in the actual industrial production process, such as the high price of high-quality powder raw materials, insufficient conversion and application of new high-quality titanium alloy systems to injection molding, and difficulty in controlling product chemical composition.

In addition, with the rapid development of microsystem technology in recent years, the demand for micro complex components applied in microsystems continues to increase. Powder injection molding needs to shift from traditional product types to micro products and develop into powder micro injection molding technology.

At present, micro injection molding technology is mostly focused on material systems such as polymers and stainless steel, and there are still many issues that need to be studied in micro injection molding of titanium and titanium alloys.

Therefore, the development of titanium and titanium alloy injection molding research should focus on the research and development of new titanium alloy systems, the development of low-cost and high-quality titanium alloy powder preparation technology, and the study of titanium material micro injection molding suitable for micro complex devices.

With the deepening of research on titanium and titanium alloy injection molding technology, it is believed that injection molding titanium and titanium alloy technology will make significant progress, thereby promoting the rapid development of the titanium industry.