Plasma deposition parameter regulation and control method based on virtual simulation

Abstract

The invention discloses a plasma deposition parameter regulation and control method based on virtual simulation, which relates to the field of drill bit welding processing, and comprises the following steps: step 1, receiving drill bit coating performance requirements and constraint indexes, setting initial process parameters, and generating an initial parameter setting scheme; step 2, constructing a three-dimensional deposition motion model based on an initial parameter setting scheme, and defining variable process parameter items in the model and a preset variation range of the variable process parameter items; 3, performing completion degree evaluation on the actual parameters of each variable item in the current period, and performing dynamic compensation adjustment on the initial parameter setting scheme; 4, based on the compensated parameters, dividing the current and the voltage into a plurality of grade intervals according to a preset rule; the optimal powder injection point is calculated in real time based on thermal field gradient distribution, the coating structure compactness and bonding strength are improved, an accurate technological parameter layered control means is formed, the stability and reliability of the deposition process are improved, and the test parameter adjustment cost is remarkably reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of welding head welding, in particular to a plasma cladding parameter regulation method based on virtual simulation. BACKGROUND

[0002] In the drilling tool industry, especially in the oil, gas and mineral resource exploitation, the drilling tool bit bears extreme working conditions such as high pressure, high temperature and wear. With the progress of material science and manufacturing technology, plasma cladding as an important surface treatment technology has the advantages of rapidness, efficiency, environmental protection and the like. Through the plasma arc, the powder material is melted and deposited on the substrate, which not only can improve the material performance, but also can realize the precise control of the coating thickness and microstructure. The rapid development of virtual simulation technology provides a new means for the optimization of complex manufacturing process. The cladding process can be accurately simulated before actual processing by using computer simulation, which helps engineers to predict the processing results and optimize the process parameters, thereby reducing the trial and error cost and improving the production efficiency. However, the existing technology relies on fixed process parameters, which is difficult to respond to the fluctuation of the molten pool caused by heat accumulation and the deviation of the powder melting state, lacks real-time sensing ability of the thermodynamic instability state of the molten pool caused by heat accumulation, lacks compensation mechanism of solid phase change induced by thermal cycle, leading to uncontrollable coating microstructure, and the current, voltage, powder feeding and other parameters are often adjusted independently, the scanning speed is fixed, and the powder melting rate cannot be dynamically matched according to the thermal field gradient, resulting in fluctuation of the molten width or uneven coating thickness. The correlation effect between multiple parameters is ignored, such as the strong correlation between the thermal field gradient and the powder feeding position. The existing current and voltage levels use fixed intervals, which is difficult to adapt to changes in material properties and process fluctuations, such as sudden changes in thermal efficiency, which can easily cause substrate deformation or substandard coating performance. When the thermal efficiency drops sharply, the fixed voltage interval aggravates the arc drift, inducing coating porosity defects. The conventional simulation model ignores the actual process boundary, making it difficult to drive real-time process decision-making. The parameter sensitivity matrix is not quantified, making it difficult to predict the critical process window and dynamically correct the powder feeding track. SUMMARY

[0003] (I) Technical problems solved

[0004] In view of the above-mentioned shortcomings of the prior art, the present application provides a plasma cladding parameter regulation method based on virtual simulation, which can effectively solve the problems of the prior art.

[0005] (II) Technical solutions

[0006] To achieve the above purpose, the present application is realized by the following technical solutions: The present application discloses a plasma cladding parameter regulation method based on virtual simulation, comprising the following steps: Step 1: receive the bit head coating performance requirements and constraint indicators, quantitatively extract the coating characteristics, set the initial process parameters according to the base material properties, powder material properties and coating characteristics, and generate an initial parameter setting scheme; Step 2: based on the initial parameter setting scheme, construct a three-dimensional deposition motion model, define the variable process parameter items in the model and their preset variable range; Step 3: evaluate the completion degree of the actual parameters of each variable item in the current cycle, and dynamically compensate and adjust the initial parameter setting scheme according to the evaluation results to form the compensated parameters; Step 4: based on the compensated parameters, divide the plasma arc current and the plasma arc voltage into several grade intervals according to the preset rules, and the grade division standard is determined according to the statistical distribution of the multi-arc welding data collected in the current cycle; Step 5: based on the compensated parameters, update and run the three-dimensional deposition motion model, simulate the melt width data and the molten pool thermal field distribution in real time, calculate the real-time offset of the optimal powder injection position based on the thermal field gradient distribution, and optimize the powder feeding position; Step 6: trigger the corresponding plasma arc current grade and plasma arc voltage grade according to the optimized powder feeding position, dynamically set the scanning speed, and automatically adjust the scanning speed to eliminate the offset when the actual powder injection position deviates from the ideal region; Step 7: cycle steps 3 to 6 until the virtual deposition simulation is completed, and output the final process parameter set.

[0007] Further, the coating performance requirements in step 1 include thickness, hardness, wear resistance, corrosion resistance and bonding strength; the constraint indicators include: maximum dilution rate, minimum heat affected zone, workpiece deformation and processing efficiency, wherein the maximum dilution rate is quantified by the ratio of the base melt depth to the total coating thickness, and the minimum heat affected zone range is determined by the isothermal line width corresponding to the Ac3 phase transition point in the thermal cycle curve; the initial process parameters include: plasma arc current, plasma arc voltage, powder feeding amount, powder feeding position and powder particle size; the coating characteristics include: thermal input sensitivity coefficient, fusion ratio critical value and thermal accumulation tolerance.

[0008] Further, when defining the variable range of the variable item in step 2, the boundary is set by the following method: The variable range of the plasma arc current is dynamically adjusted in combination with the melting point difference of the base material and the powder material, the lower limit value of the range is the minimum plasma arc current value allowed by the equipment plus the product of the melting point difference and the thermal compatibility coefficient, and the upper limit value of the range is the maximum plasma arc current value allowed by the equipment minus the product of the melting point difference and the thermal compatibility coefficient; The variation range of the powder feeding position is associated with the real-time molten pool length, and the offset is controlled in the range of 20% to 80% of the molten pool length. When the powder particle size is greater than 50 microns, the lower limit of the offset needs to be additionally increased by 5% of the molten pool length.

[0009] Further, the process of constructing the three-dimensional deposition motion model in step 2 is as follows: Based on the three-dimensional geometric model of the base workpiece, the deposition base surface is established, the mechanical structure parameters of the powder feeding nozzle and the plasma gun are combined, a three-dimensional space coordinate system including a motion trajectory is constructed, a temperature field, a phase change field, a simulated molten pool flow behavior and a powder melting state are established; The variable process parameter item is set as an edge condition variable, a parameter sensitivity matrix is generated according to a preset variation range, and the model geometric deformation and physical field evolution are driven in real time.

[0010] Further, the process of completing the evaluation in step 3 is as follows: The actual running parameter value of each variable item is obtained, and the corresponding monitoring data is collected; The upper limit value and the lower limit value of the variation range of each variable item are determined, and the center value of the variation range is taken as a reference value; The absolute difference between the actual running parameter value and the reference value is obtained, the absolute difference is divided by half of the total width of the variation range, and the quotient is converted into a percentage form as the percentage amplitude of the actual parameter value deviating from the center value; When the percentage amplitude exceeds a preset deviation threshold, it is determined that the parameter is not up to standard; All non-standard items are counted to form a compensation parameter list.

[0011] Further, the dynamic compensation adjustment in step 3 includes the following steps: A compensation function is established for each non-standard item in the compensation parameter list, and the compensation function includes a product relationship between a current offset amplitude factor and a periodic time decay factor; The output value of the compensation function is superimposed on the base value of the corresponding parameter in the initial parameter setting scheme; The compensated parameters are edge checked, the compensated parameter value is compared with the upper limit threshold and the lower limit threshold of the preset variation range, when the compensated parameter value exceeds the upper limit threshold, it is forcibly corrected to the upper limit threshold, when the compensated parameter value is lower than the lower limit threshold, it is forcibly corrected to the lower limit threshold, and when the compensated parameter value is between the upper limit threshold and the lower limit threshold, the original compensation value is retained; The parameters that pass the check are output as the compensated parameter set.

[0012] Further, the process of dividing the plasma arc current and voltage levels in step 4 is as follows: Extracting the arc welding operation data under the compensated parameters in the current simulation cycle, including: real-time plasma arc current fluctuation value, voltage sampling sequence, molten pool thermal field gradient distribution and powder melting efficiency data; The collected current and voltage data are respectively fitted with Gaussian distribution, the mean μ and standard deviation σ are calculated, and the level interval is generated with (μ±kσ) as the boundary, where the value of k is dynamically adjusted according to the position of the thermal field gradient extreme point; The number of current levels According to the formula: Determine, The upper limit value of the allowed variation of the compensated current is, The lower limit value of the allowed variation of the compensated current is, The standard deviation of the current data is, The ceiling function; The voltage level boundary is segmented according to the molten pool thermal efficiency threshold, when the thermal efficiency η<65%, the voltage interval width of each level is set to 2 ; When η≥65%, it is compressed to 1.5 , The standard deviation of the voltage data is.

[0013] Further, the calculation process of the real-time offset in step 5 is: Real-time acquisition of the molten pool thermal field distribution data output by the three-dimensional deposition motion model, extraction of the temperature change rate in the direction of the molten pool center axis as the longitudinal thermal field gradient, and extraction of the radial temperature change rate perpendicular to the molten pool center axis section as the transverse thermal field gradient; Taking the longitudinal thermal field gradient minimum point as the reference position, and combining the transverse thermal field gradient distribution to determine the annular region with the slowest temperature change; When the maximum value of the transverse thermal field gradient exceeds the preset threshold, the powder injection point is offset away from the direction with the maximum temperature change rate in the annular region, and the offset distance is inversely proportional to the transverse thermal field gradient extreme value; When the longitudinal thermal field gradient fluctuation amplitude is greater than the preset threshold, the injection point position is dynamically adjusted along the molten pool center axis direction, so that it is always in the longitudinal gradient minimum value region; The calculated spatial coordinate offset is mapped to the powder feeding nozzle motion trajectory in real time, and the powder injection position is dynamically tracked to the most stable thermal field region.

[0014] Further, step 6 matches the preset level interval mapping rule according to the optimized powder feeding position, establishes a linear correspondence between the offset value interval and the current and voltage levels, and automatically activates the associated current and voltage combination level when the offset falls within a certain numerical range. The mapping rule is generated by training historical deposition quality data.

[0015] Further, the process of dynamically setting the scanning speed in step 6 is: through the molten pool image analysis, the actual powder injection position is monitored in real time, when the actual position deviates from the ideal region determined in step 5 is detected, the speed adjustment coefficient positively correlated with the offset distance is generated, the coefficient acts on the initial scanning speed reference value to realize automatic speed reduction compensation, and the reference scanning speed is restored after the position deviation is zeroed in the continuous three monitoring periods.

[0016] (Three) beneficial effects

[0017] Compared with the known prior art, the technical scheme provided by the present application has the following beneficial effects: 1. By integrating temperature field and phase change field simulation in the three-dimensional deposition motion model, the optimal powder injection point is calculated in real time based on the thermal field gradient distribution, and the powder feeding position, plasma arc current and voltage level and scanning speed are established in linkage mapping relationship, the multi-parameter collaborative control is realized through the nozzle dynamic tracking, the defects of parameter isolated adjustment in the prior art are overcome, the coating organization density and bonding strength are improved, the production efficiency is effectively optimized and the coating performance consistency is ensured; 2. By fitting the Gaussian distribution based on the current, voltage and thermal efficiency operation data in the simulation period, the mean and standard deviation are calculated, the adaptive level interval is constructed, the voltage interval width is dynamically adjusted combined with the real-time thermal efficiency threshold, the accurate process parameter layered control means is formed, the dependence on experience setting is reduced, and the parameter adjustment precision, the deposition process repeatability and stability are improved; 3. By real-time acquisition of the molten pool state and dynamic adjustment of the plasma current, voltage, powder feeding amount, powder feeding position and scanning speed, the coating thickness unevenness, dilution rate out of control and porosity crack defects caused by static parameter setting are effectively eliminated, the dependence on artificial experience intervention is reduced, the deposition process stability and reliability are improved, and the test parameter adjustment cost is significantly reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0019] Figure 1 The flowchart of the present application. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] The present invention will be further described below with reference to embodiments.

[0022] This embodiment presents a method for adjusting plasma cladding parameters based on virtual simulation, such as... Figure 1 As shown, it includes the following steps: Step 1: Receive the performance requirements for the drill bit coating, including thickness, hardness, wear resistance, corrosion resistance, and bonding strength, as well as constraint indicators including maximum dilution rate, minimum heat-affected zone, workpiece deformation, and processing efficiency. Quantify and extract coating characteristics. Based on the substrate material properties, powder material properties, and coating characteristics, set initial process parameters to generate an initial parameter setting scheme including plasma arc current, plasma arc voltage, powder feed rate, powder feed position, and powder particle size. The maximum dilution rate is quantified by the ratio of substrate melt depth to total coating thickness, and the minimum heat-affected zone range is determined by the isotherm width corresponding to the Ac3 phase transition point in the thermal cycling curve. Coating characteristics include: heat input sensitivity coefficient, calculated based on hardness and corrosion resistance requirements; fusion ratio critical value, derived from dilution rate constraints and bonding strength requirements; and heat accumulation tolerance, modeled based on the correlation between workpiece deformation threshold and heat-affected zone range.

[0023] Step 2: Construct a three-dimensional welding motion model based on the initial parameter setting scheme, and define the variable process parameters in the model and their preset variation ranges; when defining the variation range of the variable parameters, the boundaries are set in the following way: The variation range of the plasma arc current is dynamically adjusted in combination with the melting point difference between the matrix material and the powder material. The lower limit of the range is the minimum plasma arc current value allowed by the equipment plus the product of the melting point difference and the thermal compatibility coefficient. The upper limit of the range is the maximum plasma arc current value allowed by the equipment minus the product of the melting point difference and the thermal compatibility coefficient. The range of variation in the powder feeding position is related to the real-time molten pool length, and the allowable offset is controlled within the range of 20% to 80% of the molten pool length. When the powder particle size exceeds 50 micrometers, the lower limit of the offset needs to be increased by an additional 5% of the molten pool length. The construction process of the three-dimensional cladding motion model is as follows: The three-dimensional geometry model of the base workpiece is used to establish the surface of the base to be welded, and the mechanical structure parameters of the powder feeding nozzle and the plasma gun are combined to construct a three-dimensional space coordinate system including a motion trajectory, and a temperature field, a phase change field, a simulated molten pool flow behavior and a powder melting state are established; the temperature field is calculated based on the Fourier heat conduction equation and a Gaussian distribution model of the plasma arc heat source, the VOF method is used to simulate the molten pool flow behavior and the powder melting state, the thermal physical property database is associated, and the Ac3 phase change point and the heat affected zone range are dynamically calculated; The variable process parameter items are set as edge condition variables, a parameter sensitivity matrix is generated according to a preset variation range, and the model geometry deformation and physical field evolution are driven in real time; dynamic boundaries are set for variable parameters such as plasma current and powder feeding position, the influences of material melting point difference, nozzle structure and particle size are considered, and the parameter space coverage is improved.

[0024] Step 3: The actual parameters of each variable item in the current period are evaluated for completion, the initial parameter setting scheme is dynamically compensated and adjusted according to the evaluation results, and the compensated parameters are formed; the actual parameter completion in each simulation period is quantitatively evaluated, and deviations are identified in a timely manner.

[0025] Step 4: Based on the compensated parameters, the plasma arc current and the plasma arc voltage are divided into several grade intervals according to a preset rule, and the grade division standard is determined according to the statistical distribution of the multi-type arc welding data collected in the current period.

[0026] Step 5: Based on the compensated parameters, the three-dimensional welding motion model is updated and run, the molten pool width data and the molten pool thermal field distribution are simulated in real time, the real-time offset of the optimal powder injection position is calculated based on the thermal field gradient distribution and the powder feeding position is optimized; the calculation process of the real-time offset is as follows: The molten pool thermal field distribution data output by the three-dimensional welding motion model is obtained in real time, the temperature change rate in the direction of the molten pool center axis is extracted as the longitudinal thermal field gradient, and the radial temperature change rate perpendicular to the molten pool center axis section is extracted as the transverse thermal field gradient; The longitudinal thermal field gradient minimum point is taken as the reference position, and the temperature change most gentle annular region is determined in combination with the transverse thermal field gradient distribution; When the maximum value of the transverse thermal field gradient exceeds a preset threshold, the powder injection point is offset away from the direction of the maximum temperature change rate in the annular region, and the offset distance is inversely proportional to the transverse thermal field gradient extreme value; When the longitudinal thermal field gradient fluctuation amplitude is greater than a preset threshold, the injection point position is dynamically adjusted along the molten pool center axis direction, so that it is always in the longitudinal gradient minimum value region; The calculated spatial coordinate offset is mapped to the powder feeding nozzle motion trajectory in real time, and the powder injection position is dynamically tracked to the most stable thermal field region.

[0027] Step 6: Trigger corresponding plasma arc current level and plasma arc voltage level according to the optimized powder feeding position, dynamically set the scanning speed, and automatically adjust the scanning speed to eliminate the offset when the actual powder injection position deviates from the ideal area; according to the optimized powder feeding position, match the pre-set level interval mapping rule to establish a linear corresponding relationship between the offset value interval and the current and voltage level, and automatically activate the associated current and voltage combination level when the offset falls within a specific numerical range. This mapping rule is generated by training historical deposition quality data; The process of dynamically setting the scanning speed is as follows: through the analysis of the molten pool image, the actual powder injection position is monitored in real time, and when the actual position deviates from the ideal area determined in step 5, a speed adjustment coefficient that is positively correlated with the offset distance is generated. This coefficient acts on the initial scanning speed reference value to achieve automatic speed compensation, and the reference scanning speed is restored after the position deviation is zeroed for three consecutive monitoring periods.

[0028] Step 7: Repeat steps 3 to 6 until the virtual deposition simulation is completed, and output the final process parameter set.

[0029] Compared with the prior art, by quantifying the coating performance and constraint indicators, initial parameter inversion, three-dimensional model construction, dynamic setting of multiple variable parameters, real-time evaluation and closed-loop compensation, data-driven hierarchical control, heat field gradient guided powder feeding optimization, and adaptive scanning speed adjustment, the traditional experience-based and single parameter adjustment mode is broken; The whole process is simulated and fed back online, avoiding a large amount of experimental cost, multiple parameters are coordinated to improve the coating density and bonding strength, data-driven hierarchical compensation is realized, the parameter adjustment accuracy is significantly improved, adaptive powder feeding and speed control are realized, and defects are effectively suppressed. A simulation can obtain the final process scheme that meets the performance requirements.

[0030] In other aspects, the embodiment provides a process for dividing the plasma arc current and voltage levels, specifically: Extract the arc welding operation data under the compensated parameters in the current simulation period, including: real-time plasma arc current fluctuation value, voltage sampling sequence, molten pool heat field gradient distribution, and powder melting efficiency data; Gaussian distribution fitting is performed on the collected current and voltage data respectively, and the mean μ and standard deviation σ are calculated. The level interval is generated with (μ±kσ) as the boundary, where the value of k is dynamically adjusted according to the position of the maximum gradient extreme point in the heat field gradient. The larger the heat field gradient, the smaller the value of k, and the more refined the interval division. The k value adjustment process includes: Quantify the distance between the maximum gradient extreme point in the molten pool heat field gradient distribution and the geometric center of the molten pool as a relative offset ratio; When the maximum gradient value exceeds the critical threshold, i.e., the maximum gradient value ≥ 500°C / mm, and the extreme point is located in the first third region of the molten pool, it is determined that the high-risk thermal shock state is determined, and the k value is compressed to 50%-60% of the preset reference value; When the maximum gradient value is in the medium interval, i.e., 200°C / mm-500°C / mm, and the extreme point is located in the middle third region of the molten pool, it is determined that the controllable transition state is maintained, and the k value is maintained at the preset reference value; When the maximum gradient value is lower than the stable threshold, i.e., the maximum gradient value < 200°C / mm, and the extreme point is located in the last third region of the molten pool, it is determined that the thermal equilibrium state is determined, and the k value is extended to 120%-150% of the preset reference value; If the extreme point position migrates towards the center of the molten pool for three consecutive times in the same period, an additional k value attenuation coefficient is applied, and for every 1% distance migration, the k value is reduced by 0.8%; When the real-time offset of the powder feeding position triggers system adjustment, the k value attenuation process is automatically reset.

[0031] Number of current level According to the formula: Determine, The upper limit value of the allowed variation of the compensated current is, The lower limit value of the allowed variation of the compensated current is, The standard deviation of the current data is, The ceiling function, for example, when the calculated value = 4.2, take 5 levels; The voltage level boundary is segmented according to the molten pool thermal efficiency threshold, when the thermal efficiency η < 65%, the voltage interval width of each level is set to 2 ; η ≥ 65% is compressed to 1.5 , The standard deviation of the voltage data.

[0032] Compared with the prior art, the level division standard is determined by the real-time data distribution of the compensated parameter, the non-fixed threshold, the interval width is strongly related to the thermal field gradient and the molten pool thermal efficiency, which ensures that the level division matches the actual thermal dynamics state, quantifies the parameter volatility through the standard deviation, realizes the self-convergence of the interval boundary, the greater the volatility, the wider the interval, the greater the control tolerance.

[0033] In addition, the embodiment also provides a strategy for evaluating the completion of the existing setting operation index, and a strategy for dynamically compensating and adjusting the initial parameter setting scheme, the process is: Get the actual running parameter value of each variable item and collect the corresponding monitoring data; Determine the upper limit value and the lower limit value of the variable range of each variable item, and take the center value of the variable range as the reference value; Acquire actual operation parameter value and calculate its absolute difference with benchmark reference value, divide the absolute difference by half of total width of variation range, convert the quotient into percentage form as percentage amplitude of actual parameter value deviating from central value; Determine that parameter is not up to standard when the percentage amplitude exceeds preset deviation threshold value; Statistically form a list of parameters requiring compensation from all not up to standard items.

[0034] Dynamic compensation adjustment comprises the following steps: Establish a compensation function for each not up to standard item in the list of parameters requiring compensation, the compensation function comprising a product relationship between current offset amplitude factor and period time decay factor; Superimpose compensation function output value to base value of corresponding parameter in initial parameter setting scheme; Perform edge check on compensated parameter, compare compensated parameter value with upper threshold value and lower threshold value of preset variation range, when compensated parameter value exceeds upper threshold value, forcibly correct to upper threshold value, when compensated parameter value is lower than lower threshold value, forcibly correct to lower threshold value, when compensated parameter value is between upper threshold value and lower threshold value, keep original compensation value; taking plasma arc current compensation as an example, if preset variation range is [180A, 220A], if compensated current = 230A, it exceeds upper limit, is forcibly corrected to 220A, if compensated current = 170A, it is lower than lower limit, is forcibly corrected to 180A, if compensated current = 200A, it is kept as 200A; Output parameters passing the check as compensated parameter set.

[0035] Compared with prior art, by analyzing percentage amplitude of actual parameter value deviating from central value of variation range, quantitative evaluation of deviation degree is realized, product type compensation function comprising offset amplitude factor reflecting current deviation and compensation strength decreasing with iteration number is established, both fast response to deviation and avoidance of overcompensation oscillation are realized, edge check mechanism is added, out-of-range compensation value is forcibly clamped to preset variation range boundary, risk of out-of-control compensation value in traditional method is avoided, and simulation stability is ensured.

[0036] In summary, the present application fully considers coating performance requirements and multiple constraint indicators, utilizes statistical distribution and thermal field gradient to adjust powder feeding position and scanning speed in real time, effectively improves deposition quality and stability. Through grade division and dynamic mapping, adaptive adjustment of plasma arc current and voltage is realized, ensuring that process parameters fluctuate within a reasonable range, reducing risks caused by parameter deviation, and significantly improving the intelligent level and adaptability of the process.

[0037] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling plasma cladding parameters based on virtual simulation, characterized in that, Includes the following steps: Step 1: Receive the performance requirements and constraints of the drill bit coating, quantify and extract the coating characteristics, set the initial process parameters, and generate the initial parameter setting scheme; Step 2: Construct a three-dimensional welding motion model based on the initial parameter setting scheme, and define the variable process parameters in the model and their preset variation range; Step 3: Evaluate the completion rate of the actual parameters of each variable item in the current period, and dynamically compensate and adjust the initial parameter setting scheme to form the compensated parameters; Step 4: Based on the compensated parameters, divide the current and voltage into several level ranges according to preset rules; Step 5: Based on the compensated parameters, update the three-dimensional cladding motion model and run it. Calculate the real-time offset of the optimal powder injection position based on the thermal field gradient distribution and optimize the powder feeding position. Step 6: Trigger the corresponding plasma arc current level and plasma arc voltage level according to the optimized powder delivery position, dynamically set the scanning speed, and automatically adjust the scanning speed until the deviation is eliminated when the actual powder injection position is detected to deviate from the ideal area. Step 7: Repeat steps 3 to 6 until the virtual welding simulation is completed and the final process parameter set is output.

2. The method for adjusting plasma deposition parameters based on virtual simulation according to claim 1, characterized in that, The coating performance requirements in step 1 include thickness, hardness, wear resistance, corrosion resistance, and bonding strength; the constraint indicators include: maximum dilution rate, minimum heat-affected zone, workpiece deformation, and processing efficiency. The maximum dilution rate is quantified by the ratio of the substrate melt depth to the total coating thickness, and the minimum heat-affected zone range is determined by the isotherm width corresponding to the Ac3 phase transition point in the thermal cycling curve; the initial process parameters include: plasma arc current, plasma arc voltage, powder feed rate, powder feed position, and powder particle size; the coating characteristics include: heat input sensitivity coefficient, fusion ratio critical value, and heat accumulation tolerance.

3. The method for controlling plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, When defining the range of change for the variable item in step 2, the boundary is set in the following way: The variation range of the plasma arc current is dynamically adjusted in combination with the melting point difference between the matrix material and the powder material; The range of variation in the powder feeding position is related to the real-time molten pool length. The allowable offset is controlled within the range of 20% to 80% of the molten pool length. When the powder particle size exceeds 50 micrometers, the lower limit of the offset needs to be increased by an additional 5% of the molten pool length.

4. The method for controlling plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, The construction process of the three-dimensional cladding motion model in step 2 is as follows: Based on the three-dimensional geometric model of the substrate workpiece, the surface of the substrate is established for fusion deposition. Combined with the mechanical structural parameters of the powder feeding nozzle and the plasma gun, a three-dimensional spatial coordinate system including the motion trajectory is constructed to establish the temperature field, phase transition field, simulate the flow behavior of the molten pool and the powder melting state. The variable process parameters are set as edge condition variables, and a parameter sensitivity matrix is ​​generated according to the preset variation range to drive the geometric deformation and physical field evolution of the model in real time.

5. The method for adjusting plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, The completion assessment process in step 3 is as follows: Obtain the actual operating parameter values ​​of each variable and collect the corresponding monitoring data; Determine the upper and lower limits of the range of variation for each variable item, and use the center value of the range of variation as the benchmark reference value; Obtain the percentage deviation of the actual parameter value from the center value; When the percentage exceeds the preset deviation threshold, it is determined that the parameter is not up to standard. A list of parameters requiring compensation was compiled from all non-compliant items.

6. The method for adjusting plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, The dynamic compensation adjustment in step 3 includes the following steps: For each non-compliant item in the list of parameters to be compensated, a compensation function is established, which includes the product relationship between the current offset amplitude factor and the period time decay factor; The output value of the compensation function is superimposed onto the base value of the corresponding parameter in the initial parameter setting scheme; Perform edge verification on the compensated parameters; The parameters that pass the verification are output as the set of parameters after compensation.

7. The method for adjusting plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, The process of classifying the plasma arc current and voltage levels in step 4 is as follows: Extract arc welding operation data under compensated parameters within the current simulation cycle, including: real-time plasma arc current fluctuation value, voltage sampling sequence, molten pool thermal field gradient distribution, and powder melting efficiency data; Gaussian distribution fitting was performed on the collected current and voltage data respectively, and the mean μ and standard deviation σ were calculated. The level interval was generated with (μ±kσ) as the boundary, where the value of k was dynamically adjusted according to the location of the extreme point of the thermal field gradient. Number of current ratings According to the formula: Sure, This is the upper limit of the allowable variation in current after compensation. This is the lower limit of the allowable variation in current after compensation. The standard deviation of the current data. The function to round up; Voltage level boundaries are segmented according to the molten pool thermal efficiency threshold. When the thermal efficiency η < 65%, the width of each voltage range is set to 2. When η≥65%, it is compressed to 1.

5. , This represents the standard deviation of the voltage data.

8. The method for adjusting plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, The calculation process for the real-time offset in step 5 is as follows: The thermal field distribution data of the molten pool output by the three-dimensional molten pool motion model is acquired in real time. The temperature change rate in the direction of the central axis of the molten pool is extracted as the longitudinal thermal field gradient, and the radial temperature change rate in the section perpendicular to the central axis of the molten pool is extracted as the transverse thermal field gradient. Using the minimum point of the longitudinal thermal gradient as the reference position, and combining the transverse thermal gradient distribution, the annular region with the most gradual temperature change is determined. When the maximum value of the transverse thermal gradient exceeds the preset critical value, the powder injection point is shifted away from the direction of the maximum temperature change rate within the annular region. The shift distance is inversely proportional to the extreme value of the transverse thermal gradient. When the longitudinal thermal gradient fluctuation amplitude is greater than the preset threshold, the injection point position is dynamically adjusted along the central axis of the molten pool to keep it always in the region of minimum longitudinal gradient. The calculated spatial coordinate offset is mapped to the powder feeding nozzle's motion trajectory in real time, driving the powder injection position to dynamically track the most stable region of the thermal field.

9. The method for adjusting plasma cladding parameters based on virtual simulation according to claim 1, characterized in that, Step 6, based on the optimized powder feeding position, matches a preset level range mapping rule to establish a linear correspondence between the offset value range and the current and voltage levels. When the offset falls into a specific value range, the associated current and voltage combination level is automatically activated. This mapping rule is generated through training on historical welding quality data.

10. The method for adjusting plasma deposition parameters based on virtual simulation according to claim 1, characterized in that, The process of dynamically setting the scanning speed in step 6 is as follows: by analyzing the molten pool image, the actual injection position of the powder is monitored in real time. When the actual position is detected to deviate from the ideal area determined in step 5, a speed adjustment coefficient that is positively correlated with the offset distance is generated.

Images